The Scientist Who Scans Fathers' Brains: The Parenting Checklist You NEED Before You Have Babies!

Couples with strongly correlated or synchronized cortisol levels over time report lower marital satisfaction.

"So, I have looked at cortisol interconnection in my lab between couples. So, how cortisol levels become correlated over time. I found that when couples had really strongly linked levels of cortisol, they reported lower marital satisfaction." (said at 0:57:30)

No published records could be fetched and reviewed within the search constraints to verify the guest's specific laboratory findings regarding the association between dyadic cortisol linkage/synchrony and lower marital satisfaction.

In a study using the 'Who Does What?' questionnaire, every expectant couple predicted before birth that the father would do more childcare tasks than he actually did six months postpartum.

"We gave them this questionnaire that we called "Who Does What?" where they were given 10 common baby care tasks like changing diapers, feeding a bottle, and they indicated on a slider how much mom was going to do and how much dad was going to do. And then we brought them back into the lab about six months after birth. We had them do the same scale. And it was really interesting because couples weren't actually great predictors of how much dad was going to do. So every single couple expected dad would do more before birth than dad was actually doing after birth." (said at 1:07:03)

No published record of this specific laboratory study finding—where 100% ('every single couple') of expectant couples predicted prenatally that the father would perform more childcare tasks than he actually did at six months postpartum using a 10-item 'Who Does What?' slider scale—was identified in PubMed or indexed literature. While research by Darby Saxbe and colleagues examines prenatal-to-postpartum transitions, fatherhood, and maternal/paternal division of household and cognitive labor (e.g., PMID 38951218, PMID 42097794), the specific claim appears to refer to unpublished or non-indexed laboratory data. An unverified verdict indicates that the specific published source could not be located, not that the study or finding did not occur.

Fathers who perform more infant care tasks and who use more first-person plural pronouns ('we') when discussing parenting plans report greater marital satisfaction after birth.

"we found that when dads were doing more, they reported that they were happier in their couple relationship. But one thing we looked at actually was how moms and dads talked about how they wanted to divvy up baby care. We measured how many times did they say the pronoun "we" compared to when you use the pronoun "I" where you're talking about yourself. When you're using "we," you're talking about, you know, you and your partner. The more we-ness the dads were showing, the more happy they were in their relationship after birth. So, their investment, their willingness to chip in, even if they didn't totally realize all their plans, was still linked with their satisfaction. And that was controlling for how they felt about their partner before birth." (said at 1:07:38)

A systematic search of PubMed and Europe PMC records for research by Darby Saxbe and colleagues on paternal pronoun use ('we-ness' / first-person plural pronouns during parenting plan discussions) and postpartum relationship satisfaction did not return a published record indexed in the queried databases matching this specific study finding. This does not prove the claim false, as the finding may be in press, published in an unindexed specialty/psychology journal, or presented in conference proceedings, but it cannot be verified against the available biomedical literature.

Studies evaluating female preferences for male body types show that women find 'dad bods' attractive and associate them with being more hands-on, attentive, and caring fathers.

"Studies of single women have found that, you know, if you show them a series of body types, the dad bod is the most popular, you know, sort of like a mildly, you know, kind of like uh lightly marbled male torso... But part of it is if you show women torsos of different kinds of male body types, the the sort of dad bod is one that women say he's more likely to be a hands-on father. He's probably going to be more attentive. He's going to be more caring." (said at 1:17:59)

No published peer-reviewed scientific studies matching this claim were identified in PubMed or Europe PMC. While informal dating app surveys and commercial media polls (such as annual surveys commissioned by fitness chains) have frequently discussed public perceptions of the 'dad bod,' there is no published scientific literature demonstrating that single women rank the 'dad bod' torso as the most popular body type or empirically associate it with being a more hands-on, attentive, or caring father.