041: Siblings: Why do they fight, and what can we do about it?

Hot on the heels of our last episode on whether only children really are as bad as their reputation, this week’s episode is for the 80% of families (in the U.S., at least) who have more than one child.

How do siblings impact each other’s development?  What should we make of the research on how birth order impacts each child?  Why the heck do siblings fight so much, and what can we do about it?  (Turns out that siblings in non-Western countries actually don’t fight anywhere near as much…)

We cover all this and more with my guest, Professor Susan McHale of Penn State University.


Note: Professor McHale mentions a helpful book written by Judy Dunn at the end of the episode but doesn’t specifically name the title; Dunn has actually written a number of books on siblings which can be found here.



Bjerkedal, T., Kristensen, P., Skjeret, G.A., & Brevik, J.I. (2007). Intelligence test scores and birth order among young Norwegian men (conscripts) analyzed within and between families. Intelligence 35, 503-514.

Branje, S.J.T., van Lieshout, C.F.M., van Aken, M.A.G., & Haselager, G.J.T. (2004). Perceived support in sibling relationships and adolescent development. Journal of Child Psychology and Psychiatry 45(8), 1385-1396.

Dixon, M., Reyes, C.J., Leppert, M.F., & Pappas, L.M. (2008). Personality and birth order in large families. Personality and Individual Differences 44, 119-128.

Dunn, J., & Kendrick, C. (1980). The arrival of a sibling: Changes in patterns of interaction between mother and first-born child. Journal of Child Psychology and Psychiatry 21, 119-132.

Dunn, J. (1995). From one child to two: What to expect, how to cope, and how to enjoy your growing family. New York, NY: Ballantine.

Feinberg, M.E., Solmeyer, A.R., Hostetler, M.L., Sakuma K-L, Jones, D., & McHale, S.M. (2012). Siblings are special: Initial test of a new approach for preventing youth behavior problems. Journal of Adolescent Health 53, 166-173.

Healey, M.D., & Ellis B.J. (2007). Birth order, conscientiousness, and openness to experience: Tests of the family-niche model of personality using a within-family methodology. Evolution and Human Behavior 28, 55-59.

Jensen, A.C., & McHale, S.M. (2015). What makes siblings different? The development of sibling differences in academic achievement and interests. Journal of Family Psychology 29(3), 469-478.

Kristensen, P. & Bjerkedal, T. (2007). Explaining the relation between birth order and intelligence. Science (New Series), 316(5832), 1717.

Lawson, D.W., & Mace, R. (2008). Sibling configuration and childhood growth in contemporary British Families. International Journal of Epidemiology 37, 1408-1421.

McHale, S.M., Bissell, J., & Kim, J-Y. (2009). Sibling relationship, family, and genetic factors in sibling similarity in sexual risk. Journal of Family Psychiatry 23(4), 562-572.

McHale, S.M., Updegraff, K.A., Helms-Erikson, H., & Crouter, A.C. (2001). Sibling influences on gender development in middle childhood and early adolescence: A longitudinal study. Developmental Psychology 37(1), 115-125.

McHale, S.M., Updegraff, K.A., & Whiteman, S.D. (2012). Sibling relationships and influences in childhood and adolescence. Journal of Marriage and Family 75(5), 913-930.

Palhaus, D.L., Wehr, P., & Trapnell, P.D. (2000). Resolving controversy over birth order and personality: By debate or by design? Politics and the Life Sciences 19(2), 177-179.

Rohrer, J.M., Egloff, B., & Schmukle, S.C. (2015). Examining the effects of birth order on personality. Proceedings of the National Academy of Sciences 112(46), 14224-14229.

Solmeyer, A.R., McHale, S.M., & Crouter, A.C. (2014). Longitudinal associations between sibling relationship qualities and risky behavior across adolescence. Developmental Psychology 50(2), 600-610.

Updegraff, K.A., McHale, S.M., Killoren, S.E., & Rodriguez, S.A. (2011). Cultural variations in sibling relationships. In J. Caspi (Ed.), Sibling Development: Implications for Mental Health Practitioners. New York, NY: Springer.


Read Full Transcript


Jen     [00:38]

Hello and welcome to the Your Parenting Mojo podcast. Regular listeners will recall that this is the second episode in a two part series, which was prompted by a listener emailing me to say that she and her partner don’t want to have another child, but they’re worried about the impacts of not having siblings on their daughter. We looked at that topic last week, but I didn’t think it was fair to the other 80 percent of the families in the country, assuming all of them are listening who have more than one child. So today’s episode is for all of you. I’d like to extend a warm welcome to my guest, Susan McHale, Distinguished Professor of Human Development and Family Ptudies and professor of Demography – among other things – at Penn State University. Research in her lab focuses on family systems, dynamics including youths and parents, family roles, relationships and daily activities, and how these are linked to family members’ psychological and physical health and development. Her lines of research includes sibling relationships, family, gender dynamics, and the sociocultural context of family dynamics. And since we’ve already done episodes related to those second two topics, I’m especially interested to learn about how all of these come together and are intertwined with the idea of siblings. Welcome Professor McHale.

Dr. McHale:    [01:47]

Glad to be here.

Jen:   [01:48]

All right, so I wonder if we could kind of start at the end in a way with the developmental outcomes of signaling relationships and then work our way back to the beginning because there’s way more research on the developmental outcomes than I could have imagined. I wonder if you could summarize some of the state of the current research on several different things and we can kind of work our way down a little list that I have here. I’m the first one being risky behavior like adolescent sex. I had no idea that siblings was related to that.

Dr. McHale:  [02:17]

Right. Most of the research has been on sibling resemblance and of course siblings are genetically related; it’s not just a social process and some work has been trying to disentangle the role of shared genetics and shared environments in sibling similarity and all kinds of risky behavior from substance use to adolescent sex. I don’t think there’s quite a definitive answer. Usually behaviors are complex and so multiply determined so there’s likely to be some genetic load and some socialization between siblings as well as growing up in the same family that all come together in helping to explain sibling resemblance. In our research, we’ve tried to study the processes through which siblings become more alike or more different from one another by actually asking siblings whether they try to be like one another or whether they try to de-identify or work to be different from their siblings, try to be different because they don’t want to be the same kind of person that their sibling is and what we see is that in sibling relationships that are warm and positive, siblings are more likely to say that they try to be like one another and so on the one hand a positive sibling relationship has good outcomes because siblings can be sources of support, affection and so forth. On the other hand, if you have a sibling who’s really into risky behavior, a warm and close sibling relationship isn’t always a good thing.

Jen:   [03:56]

And so you see the warm relationship leading the, I assume usually the younger child to model the older child’s behavior?

Dr. McHale:    [04:04]

Correct. So constructs like partners in crime, older siblings being gatekeepers to availability of substances or relationship partners. These are all ways that siblings can influence one another.

Jen:     [04:20]

Is that linked to the idea of gender development as well, and I’m just wondering if maybe there’s a younger boy who has an older girl sibling. Do you see that the boy is kind of more socialized to be around women and are there influences that the older girl has on that younger boy?

Dr. McHale:  [04:38]

Yes. Oftentimes our sample sizes are too small to study the four siblings constellations, brother, brother, sister, sister, and so forth. Older sister, younger brother, younger sister, older brother. But we have some emerging information. I’m one of the dyads that has some longstanding findings that warmth and affection can lead to problems is the brother, brother dyad. So an older brother who’s close and warm with a younger brother can lead that child into, or they can mutually influence one another, sort of playing off one another, getting into trouble, deceiving parents, doing things behind their parents’ backs and so forth. So, so the older brother really can be something of a risk factor. On the other hand, some of our studies have found that older sisters are are protective. This is a study of Mexican origin families that kids who have had both boys and girls who had older sisters were protected in their acculturation into U.S. society in terms of engaging in risky behavior.

Dr. McHale: [05:49]

One of the other, I think pretty interesting findings has to do with mixed-sex dyads, so brother, sister, sister, brother, where we found that in terms of romantic competence, being able to relate to the other sex possibly not surprisingly growing up with a sibling of the other sex and all that that involves, you know, having your siblings friends around just being used to having members of the other sex in your orbit, that by the time you reach the end of adolescence, kids who have the other sex in their lives by virtue of having a sibling of the other sex tend to feel more competent in the context of heterosexual relationships. So it’s a mixed bag. Like most things, it’s not all good things are related, but there are some good things and some potentially not so good things that come out of the same experiences.

Jen:  [06:42]

Yeah. And some of the ones that really surprised me were differences in health outcomes among siblings. How does, how can siblings impact your health?

Dr. McHale: [06:51]

Well, are you thinking about the study of Mexican origin?

Jen:      [06:57]


Dr. McHale: [06:57]

And that’s not necessarily about what siblings do, what it’s about being a girl or a boy, and the gender socialization that is involved in this, as I said, was a study of Mexican origin families were the findings showed and Kim Updegraff who’s at Arizona State University was the lead on this study, but the findings showed that when mothers had more traditional gender attitudes, you know, women’s place, whereas in the home, men are the ones in charge, that kind of thing, their daughters were substantially less likely to access healthcare in their young adult years. So this is predicting out over about eight years where early experiences in a highly gendered environment that put men, you know, at the forefront end put women as more subservient were, were linked to how these young women were taking care of themselves a number of years later.

Jen:     [07:56]

Wow. Uh, that is a very surprising finding. And so you’re, you’re speaking about a study of Mexicans; Mexican siblings, and that leads me to wonder if it’s possible to generalize, I know this is a big generalization, but how do sibling relationships differ across cultures in general?

Dr. McHale:   [08:20]

They do considerably and we’ve only directly studied sibling relationships in families living in the United States. So the Mexican origin live near the Phoenix area. We have a group of about 200 African American, two-parent families in the Baltimore/Philadelphia area. And then we have a sample of predominantly Anglo families in central Pennsylvania. So these families differ not just by ethnicity, but where in the country that they’re living in rural, urban and so forth. So it’s directly don’t make direct comparisons, but we’re much more interested in how cultural values and practices that we measured directly are linked to sibling relationship quality. And so for example, Mexican origin families have been described as being more gender stereotypical. And so therefore the traditional attitudes of mothers reflect the cultural orientation to discriminate between the roles and practices and daily activities of men versus women, girls versus boys and so girls may be more likely to pick up on these messages in those families leading to the differences in healthcare access. I should also mention that it’s not all good things for the boys and those families either in general, the young men in that sample access healthcare less than the young women, so we could explain the differences between the young women in that those Mexican origin families, by their mothers’ gender attitudes, but all it took for the boys was being a boy and they were less likely to access healthcare, which is, you know, what are sort of a stereotype of men refusing to go to the doctor.

Jen:   [10:05]

Right. Okay. So it’s not that they’re not accessing it because they’re not sick, it’s that they, they should be accessing it and they’re not.

Dr. McHale:   [10:12]

Well, they’re just not getting routine physical exams.

Jen:  [10:14]


Dr. McHale:   [10:15]


Jen:    [10:16]


Dr. McHale:  [10:16]

But in, in those families, also Mexican origin families are, are known for their families and values as are many minority groups in the U. S., African American families included and our studies of those African and Mexican origin families show that when siblings and their parents have stronger familism values, that is, they see the family as central to their lives and obligations and responsibilities to the family as being highly important, distinguishing between communal oriented or family oriented set of values and a more individualistic me-first, independence, individual achievement-oriented society like traditional mainstream U.S. culture, this orientation to family is linked to more positive sibling relationships.

Jen:    [11:10]

Okay. And so I guess we’re, we’re skipping ahead a little bit here is planning on winding up to this, but since since we’re there now, let’s go ahead and talk about it. So I’m curious about this kind of love-hate dynamic that seems to go on between siblings and when I put an email out to my listeners and said, you know, do you have any questions about siblings that I should ask my expert next week? I got some responses and it seemed like a lot of them were related to my siblings just can’t get along. One person gave an example of a three year old daughter snatching a toy out of a nine month old son’s hands, not because she wants the thing, but just because he has it and she doesn’t or she doesn’t want the younger child in her space, even when they’re just kind of in the same room. Is the older child looking for our attention because I’m thinking about the ethnographic research I’ve seen in countries like Mexico where five or six siblings will play together all day while both the parents are at work and I’m sure they have disputes occasionally, but for the most part they’re kind of responsible for each other and they just all seem to get along and I’m curious about how the cultural construct of the family… what implications that has for the ways siblings get on or don’t get along with each other.

Dr. McHale:    [12:23]

Well, and comparisons haven’t been directly made, but anthropologists who study sibling relationships in other countries have suggested that sibling rivalry is a Western invention.

Jen:   [12:35]

Oh really?

Dr. McHale:    [12:36]

For a couple of reasons. First, the families and values, putting your family before yourself. You know, the group before the individual mitigates against this idea that this is mine and that’s yours. In some cultures, kids don’t have property, right? They don’t have their own room, they don’t have their own toys, whatever the family has belongs to the family. And so the idea that you can’t have it because it’s mine or that I should have it, but you shouldn’t is, you know, a very individualistic, you know, personal achievement oriented ethic; it comes from that and there are good things and bad things that come from that ethic, right? But you know, it’s a package deal and if you’re promoting individuality, self esteem, a sense of self, that is very positive, it can mitigate against being one with the group and that whatever is mine is yours and if you’re happy, I’m also happy to. These are the, these are the two sides of the coin here. Trying to get at both would be ideal, but it’s, it’s not that easy. The other reason why other cultures may not have the same kind of rivalry is because roles are defined by gender and age. Often in other cultures, siblings are primary caregivers. Like your example of the Mexican families in Mexico where an older sister or cousin – it’s usually girls – are responsible for their younger siblings, cousins, children in their community is not a large group, but, and while the parents are working at home, in the fields or whatever, and in that role these girls are setting expectations and maybe bossing younger children around, but they’re responsible for their wellbeing.

Dr. McHale:   [14:24]

So it’s not the case of whether you can have this toy or I can have this toy, but how we can get through the day with a minimum of fuss. So these girls have an established sense of, of responsibility and authority and other cultures. There’s discrimination based on males versus females and a first born boy it has the high status and can basically tell a sister, no matter how old she is, what to do and that’s legitimate. And so there is not conflict and arguments because people know their places; they know their roles. And there’s not a, it’s not a question of arguing about it in U.S. mainstream culture, equal relationships are, are, can be hard to figure out. Everybody has to, has to figure it out every day on their own. There’s not an established practice which makes it much more difficult to negotiate. Especially little kids. Right?

Jen:    [15:27]

Yeah. So I just digging even deeper into that. I’m just thinking about something I read in one of your book chapters where you said that patterns of emotional intensity, by which I assume you mean fighting?

Dr. McHale: [15:41]

Or it could be highly positive.

Jen:     [15:42]

Oh, okay.

Dr. McHale:   [15:43]

They’ll have a laugh and joke and in only your sibling can understand your sense of humor and the things that usually funny, right? So it’s very positive but also very negative.

Jen:   [15:53]

Okay. Okay. So that emotional intensity might be a result of a cultural expectation that family members are warm and supportive here in kind of western cultures, but also that there is this cultural norm promoting competition and individualism and that together those kind of support a love-hate dynamic. And that seems as though it forms another layer on top of the idea that your siblings are essentially peers in a relationship rather than one being the boss and the other one being told what to do and that those two things together form even more attention between the siblings of things that they have to figure out, is that right?

Dr. McHale:  [16:31]

More intensity. Right. So people, you know in the context of peers, especially in childhood, most of the time kids are supervised when kids are at home, the likelihood that they’re constantly supervised, unless they’re very, very young is not so great. And so kids can let their hair down and as I said, it can be very, very positive goofing. And that’s oftentimes what you see is kids are playing around and then somebody gets hurt, either their feelings or their body and a really joyous romp turns into anger and tears in moments. And so you get these very high highs and very low lows in ways that you don’t necessarily with peers.

Jen:  [17:13]

And so it almost seems to me if we’re asking, you know, what do I do about getting my children to fight less, we might be asking the wrong question because it seems as though if the purpose of the fight or the argument or the dispute is your children are trying to figure out how they relate to each other and what is their place in the world, and they’re kind of negotiating that on an ongoing basis. That’s what’s happening when they’re “fighting” and that if you take away that from them, then you’re taking away the tool that they need to figure that out. Is that right?

Dr. McHale: [17:48]

Well, I would say that parents can have a huge role in helping children learn problem solving and conflict resolution skills.

Jen:   [17:55]

Right. Yeah.

Dr. McHale:  [17:56]

So the fact that there’s a difference of opinion is an opportunity for development, but it has to be carefully handled. You can’t leave three year olds and five year olds and eight year olds to do this on their own. Parents really need to be in there serving as the coach and the mediator to help kids understand why they’re feeling the way they are, help them understand how the other person feels, help them come up with a solution to the problem that they both can live with and this is a really key role for parents. It’s basically it’s social skills training. I mean parents are modeling these kinds of behaviors in their own relationships, so kids who see their parents having a difference of opinion in their marriage and that difference of opinion is resolved and the family goes on there in a different situation than kids who see their parents fighting and going off in a huff.

Dr. McHale:  [18:53]

And so same thing with siblings. You know, the difference of opinion is, is an opportunity or it’s a threat and depending on how parents handle it, kids are not going to be doing this automatically unless they see it being modeled. Unless their parents can help them through coaching… I think I did send you a paper up where we described an intervention to promote positive sibling relationships.

Jen:     [19:20]

Yes, you did.

Dr. McHale:    [19:21]

And a major component of this intervention by Mark Feinberg, another colleague of mine is the lead on this project, was to, was teaching kids social skills.

Jen:   [19:30]

And so can you tell us about that and what was the intervention and what was the result?

Dr. McHale:   [19:35]

Okay. So there are these kinds of peer interventions in schools for young children, preschool to school, Young, young school, age years. And so ours was built on some work in schools with peer relationships that our colleagues Karen Bierman and Mark Greenburg have developed over many years, but we modified it to focus on sibling relationships.

Dr. McHale:    [20:01]

So this particular relationship with both kids involved and issues like being able to recognize your emotions. When you start feeling bad, stop. Think about how you’re feeling. Think about why you’re feeling that way. Don’t just react. Try to understand how the other person’s feeling because you tell how you feel so the other person knows. Sometimes they may be teasing you and not realizing that you’re feeling badly about it or that they’ve taken your favorite whatever it is and don’t realize how hurtful that was. So stating your feelings, hearing the other person’s feelings, stopping – and and we we teach social problem solving. So what are some that you think would be a good solution to this potential conflict? What does the sibling think? What would work best for both of you? So how do you make a deal that you both can live with and then making that deal.

Dr. McHale:   [21:01]

Seeing how it works. I mean it’s pretty basic, but kids need practice doing it. It’s not the automatic first thing that they do. They need to be supervised and need to be encouraged and that was a major part of the intervention were both kids were learning how to behave toward one another. It’s not good enough for one kid to learn and the other one to not know the routine. Getting both kids to learn how to handle these situations which are going to come up. That’s all there is to it. And having this be a new family routine, this is how our family deals with conflict. We also talked about major sibling issues like differential parental treatment, which we know can lead to jealousy and negative sibling relationships. We talked to children; we asked them to develop pictures about the things that are the characteristics that they shared and characteristics that made them unique.

Dr. McHale:    [21:57]

They came up with a team mascot that describe what their family was like, how their family was special. We developed timelines that showed when certain privileges were allowed in their family so younger siblings could see that, you know, when I’m nine years old, I can go on a sleepover because that’s what is that kind of thing. I can ride my bike around the block. Those kinds of things that they may be envious that their older sibling is doing that now. But see that, that is in store for them in the future. So it was a generic social skills training for kids, but also some special issues having to do with siblings.

Jen:   [22:33]

Okay. And what were the results?

Dr. McHale:    [22:35]

Well, we did find that according to parents reports the children were getting along better and we had some videotape observation data and those data also suggested that the children were getting along better in comparison to a control group that didn’t have the intervention. One of my favorite findings, however, was that the mothers in the intervention group became less depressed.

Jen:   [23:02]


Dr. McHale:   [23:03]


Dr. McHale:  [23:06]

The biggest effect. And you know, these constant squabbles between siblings. So you know, it’s not like their kids are beating one another into the ground, but it’s just the constant, constant, constantness of siblings… Some of our colleagues have reported that sibling conflict is parents’ number one child rearing concern.

Jen:   [23:25]

Yay for only having one! So you did make that study available to me and so of course I’ll put it in the link available in the links in case anyone is interested in checking that out. As you were telling me about it though, I’m thinking it sounds an awful lot like the book, How to Talk So Kids Will Listen and Listen So Kids Will Talk. Are you familiar with that?

Dr. McHale:   [23:42]

I know of it. I have not read it.

Jen:    [23:45]

So the kinds of skills that you are describing teaching children are very similar to the ones that are in that book and there’s a new version out, How to Talk so Little Kids Will Listen right now and I did an interview with the co-author of that a few weeks ago, so parents might want to go back and listen to that episode.

Dr. McHale:   [23:59]

And you’re trying to get children to be able to do it with one another as opposed to adults doing it to the children. It’s great for parents to do that because it is modeling I messages saying how you feel in non blaming terms and that kind of thing, but it’s teaching young children to do it dyadically.

Jen:     [24:17]

Yes. Yep. Equipping them with the skills and then showing them how to use them. So less depression as a result. That’s pretty positive finding.

Dr. McHale:   [24:25]

Oh, and teachers also reported independently that children were doing better in school; the individual behavior of the siblings improved.

Jen:   [24:35]

Okay. So the trick then it seems is when your kids start fighting again is not to say, “oh, not again,” but “this is an opportunity!” and to use it as a teaching moment.

Dr. McHale:   [24:46]

Yeah, some of our research shows punishing them and you know, go to your room. That kind of thing doesn’t help. They need to know what to do, not just what not to do. Right?

Jen:   [24:55]

Yeah. Yeah. That was, that was another question I had for you as well, which is we’ve talked to a fair bit on the show about punishment and how the lesson, the child learns from that punishment is very rarely the one the parent intends to teach is that I assume the case with siblings as well. And it, does the dynamic play out any differently when there are siblings involved? When you’re talking about punishment?

Dr. McHale:    [25:16]

Well, I think it can be easy to go wrong. I mean, one of the really important things is not to take sides when there’s a sibling conflict because that’s just going to exacerbate the rivalry, but that’s tricky if you are pretty sure that you know who’s causing what, but why is that child causing the problems between the siblings? Well, you know, it may feel me because they feel that the, uh, uh, their brother or sister is the favorite and one really great way to engender sibling conflict is through differential treatment and having a favorite.

Jen:     [25:49]

Okay? But I mean deep, deep, dark inside, don’t most parents have a favorite?

Dr. McHale:   [25:56]

Um, yes. When we asked parents about differential treatment and favoritism, most parents report that they do treat their children differently, so that’s one thing. They’re more likely to treat their children similarly in the domain of affection than they are in domains like shared time or discipline or privileges or chores, allocation, that kind of thing. But nonetheless, parents will agree that they’re more affectionate to one child and the other, but that changes over time. And so the child who gets more affection at one age may not be the one who gets more affection at a later age and you mothers and fathers may differ in terms of who they’re more affectionate with. We know that when children think that the parents treatment is fair, even if parents are saying that they treat their children differently, children don’t show the same negative reactions. You may have a child who’s very independent and very pure focused out of the home and that child may just not need the same kind of affection and attention as another child who’s a little bit shyer and less peer-oriented.

Jen:  [27:16]

Okay. So, so as long as the siblings themselves see that difference, but recognize it as being fair to themselves, then it’s okay for that differential treatment to occur. Is that what you’re saying?

Dr. McHale: [27:26]

Uh, the, the negative implications are less pronounced. I would say the other thing is that talking openly about differential treatment and families could be a good thing because when children understand reasons for differential treatment it’s less likely to have the same negative consequences.

Jen: [27:43]

Okay. So along the lines of the description you gave about, you know, when I’m nine, I’ll get to go to a sleepover as well. And seeing that it’s not just an arbitrary decision that older brother gets to go and, and I don’t.

Dr. McHale: [27:57]

And one of the reasons for differential treatment the kids can make sense of is if one sibling needs something more than the other, I mean obviously they can go too far, and somebody can get neglected. But if a child is going through a tough time or a child has characteristics, even, you know, a learning disability that requires extra parental attention and time that needs to be explained. You know, you might think other kids are picking up on it, but they may not. You may think that you’re protecting the child with the special need by not talking about it, but kids notice; they notice from a very, very young age that one child is getting treated differently. Three years old or even younger. They can detect differential treatment by their parents. And so rather than trying to pretend like you’re not doing it, talking about it and explaining why is probably optimal.

Jen:     [28:49]

Okay. That’s a key lesson for parents of siblings, I think. And I’m just thinking back to an episode that we did on race a long time ago now, and I’d always assume that if you just don’t talk about race, then it won’t be an issue, and of course I recognize it’s my White privilege that allows me to do that. And when I started learning about the research on it, it turns out that actually no, that’s a great way to raise a racist child. So yeah. So, so getting things out in the open and having a conversation about them, even if it probably feels uncomfortable to parents to acknowledge that yes, I’m treating your sibling differently to you is important.

Dr. McHale:  [29:23]

And, and listening to the child, the child might have some solution that would make her feel really fine, you know, it’s okay if you do this and that, but if you could just do this with me, then I would feel better. Good to hear that.

Jen:   [29:35]

Yeah. And actually act on the child suggestions as well. Yeah. Okay. Um, so switching gears a little bit, I want to try and make some sense of the research on birth order because there was so much of it out there that honestly I really couldn’t get my head around what was, what, there was some research saying that opposites attract and the first borns should only married last borns, which I hope doesn’t spell divorce from my husband and I because we’re both firstborns; the first borns are high achievers. The middle children have social pleasers and the last borns are the fun loving ones. But then there was also research saying that the big five personality traits which are supposed to measure kind of most of what a person’s personality is, which are openness, conscientiousness, extroversion, agreeableness and neuroticism, and that sibling birth order has no impact on that whatsoever. And other studies saying it has a huge impact on that. And so what on earth we to make of that kind of body of research.

Dr. McHale:  [30:34]

Um, how can I answer that? It’s, it’s a..

Jen:     [30:39]

A work in progress?

Dr. McHale:  [30:41]

Uh, well, I’m not sure even about that.

Jen:   [30:46]


Dr. McHale:   [30:46]

I’ll tell you, when I first started my career, most of what was in the literature on siblings was about birth order and it was so boring. I imagined on a steady siblings until I started trying to understand how siblings treated one another and how they experienced their families. My question is how does birth order translate into personality? How does birth order translate into anything? It happens because of how children are treated in families. It’s not automatic, it’s not magical, and so if you know that children who get more attention and whose parents who have lots of adults talking to them, score higher on achievement tests, then the way to do that for all of your children is to make sure that they get plenty of time talking to adults. It’s harder when you have a second child then when you only have one and that’s the only kid who’s who’s around, but it doesn’t mean that – this is about intellectual achievement, now – it doesn’t mean that a later born can’t achieve the same as a firstborn. I don’t think that the data on personality differences as a function of birth order are strong at all. I really don’t. I, I, uh, I, you know, I, it, it’s almost like astrology from what I can tell.

Jen:   [32:16]

Okay. Uh, definitely science to some people who believe in it,

Dr. McHale:    [32:22]

But, you know, if you look at the large studies and you look at studies that compare children from the same family, not just children from different families. You don’t see as much in the way of clear cut personality differences. People are just so much more complicated than something like birth order explaining a whole lot. And as I said, there’s just so many experiences in families and in sibling relationships that could or may not create those really those differences in outcomes. I think the more interesting question is what is it about family that gives rise to intellectual achievement or conscientiousness? And so understanding for me, the conditions under which two siblings will try to be alike so that they’re both conscientious versus families were siblings try to be different from one another. So that one is, and one is not conscientious to me, those are the interesting questions. Not that it’s somehow magically connected to birth order.

Jen:   [33:27]

Yeah. Okay. So just digging a little bit more into the intelligence example because we actually looked at that in the last episode on only children and did find that the research on only children showing that they tend to score better on intelligence tests and I think the reason that researchers have posited for that is because they do spend time with adults having adult conversations using sophisticated vocabulary and as the parents have more children, the general conversation level seems to get pulled down to the capability of the lowest member. And so it seems to me what you’re saying is to think about what are the qualities that you feel are important and that you want to foster in your child and how can you provide for those even though you do have more than one child. So maybe your second child gets to go and spend time with grandparents once a week or something and with no other children around and have conversations about things that they’re interested in. Or is that one way of getting at that kind of thing,

Dr. McHale:     [34:24]

Right. The findings that you’re talking about are consistent with what’s been termed the resource dilution hypothesis basically that the more siblings that you have, the more children that you have in a family, the lower the average achievement. So it’s not just that the first ones are the highest achieving, but that, you know, as you go down the birth order, kids will lose ground. I’ve seen studies showing that, well, there’s one paper showing that children, um, in Mormon families you do not see the resource dilution effect. This is a culture where large families are valued and it’s a communal oriented culture where there’s a lot of adults who are interested in children and in an individualistic culture where, you know, every family is an island. Every nuclear family is an island and you know, you’ve got one or two parents and one point whatever it is, children for the parents to rear, far away from nuclear family, not necessarily connected to a community of adults to back the parents up and to be there for the parents. Then of course you’re gonna be able to see that or strongly so depending on the larger context within which a family is embedded, you’re likely to see different effects based on things like birth order, gender, numbers of children, only children and so forth. The other thing I would say is that researchers tend to look at child outcomes one at a time. So one group studies intellectual development, one group study, social development, and you know, kids come in a package.

Jen:    [36:07]

Oh they do? Fights and all?

Dr. McHale:    [36:11]

So, you know, in terms of achievement, a point on an IQ test versus a kid who knows how to negotiate difficult social situations and is one or two points lower- who’s the higher achieving child, who’s going to be higher achieving child? And we need to think more about the totality of the child’s experiences rather than these sort of, one at the time outcomes without understanding what the whole context of the child’s life is likely to lead to.

Jen:      [36:40]

Yeah. Which is much more difficult to do in a sort of objective, scientific way. Which is an interesting question to be studying for your life.

Dr. McHale:   [36:50]

I often have this perspective that as, as my colleagues and I put it, all good things are correlated, that good parents, good kids and a kid is good at this, is also good at that. But you know, when you look closely at people’s lives, families and individuals, we’re constantly making trade offs. You can, you know, achieve here, but that means you can’t do so well there. You can invest in this. But that means you don’t have enough time, money, whatever it is to invest in that. We’re constantly making these trade offs and a lot of our studies, because we look at one thing or one person at a time, it’s easy to think that there’s one right way to do it and if you only do this, good things will happen. But for any parent who’s had more than one child, you begin to realize that the parenting books, which tend to focus on rearing a child, although they are increasingly including a chapter on siblings, it’s a lot harder when you’ve got multiple kids because the things that you do to promote the wellbeing of one child may or may not promote the wellbeing of the others.

Jen:   [37:56]

Mhmmm. This is sort of a question of interest, not that not for me because I’m not having a second child, but I’m wondering about how important it is to be mindful about those trade offs and just be aware that they’re happening or is it just kind of something that happens in the background and parents aren’t really aware of it and maybe they realize years after that this decision they made for this child impacted the other child in that way. What do you think about that?

Dr. McHale:   [38:23]

Well, that’s a very good question. I do think people’s lives are very busy and most parents are running just to stay in place. And the idea of having the time to think through what you’re up to, that that seems like a luxury. Oftentimes there are intervention techniques that are now being promulgated on mindfulness, which is about being in the moment and paying attention to where you are now and not being distracted by, you know, what your meeting is going to require of you tomorrow morning at [7:00], that kind of thing. Maybe that will mean that it has the data that are available suggest it can be really good for parents, for teachers, for kids themselves. Because you’re thinking more about now as opposed to, as you said, getting distracted about other stressors in your life or other adventures in your life. Maybe that will make a difference. Time will tell.

Jen:   [39:19]

Yeah. Okay. So as we conclude here, I wonder if there’s a nugget of wisdom that you would like to confer upon parents of siblings.

Dr. McHale:    [39:29]

Oh my. I think just like parents who are invested in their children think a lot about how to promote the wellbeing of their individual children. Thinking about how to parent siblings is a different topic. And this sort of one at a time, here’s what I do for this one, this one, and this one doesn’t always some two or doesn’t some to how we treat the siblings as a group and how we parent the siblings, but the parenting of siblings is just as important and challenging as the parenting of individual children, I would say, and deserves the same level of attention and investment. Does that make sense?

Jen:   [40:15]

It does, yeah. I’m wondering if there’s a specific resource or book or something that you might recommend for people who are interested in learning more about that.

Dr. McHale:  [40:23]

One of my colleagues, but Judy Dunn wrote a book about the transition to becoming a sibling that was in the late nineties and Judy was one of the most prolific and insightful researchers scholars that studied sibling relationships ever, so I would highly recommend that book [note: Judy Dunn actually wrote a number of relevant books that you can find in the references].

Jen:  [40:42]

Okay. Thank you so much for sharing your time and your resources with us and I hope that I never have to put this advice to good use, but I feel as though you’ve really given parents tools and concrete strategies that they can use to not just do well by one child, but to do well by their siblings as a, as a team, as a family. So I’m so grateful for your sharing that information with us.

Dr. McHale:   [41:04]

Well, thank you for having me. I would say in my own life, my siblings were the best present my parents ever gave me and I was glad to be able to do that for my children.

Jen:   [41:12]

Ah, so I’m being undercut the last minute!

Dr. McHale:  [41:18]

You can cut it before my words of wisdom.

Jen:  [41:19]

Yes. Awesome. Well thanks again and I just want to remind listeners that references for the show today can be found at YourParentingMojo.com/siblings


Also published on Medium.

About the author, Jen

Jen Lumanlan (M.S., M.Ed.) hosts the Your Parenting Mojo podcast (www.YourParentingMojo.com), which examines scientific research related to child development through the lens of respectful parenting.

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