Assuming no freak hospital mix-ups, mothers can be 100% sure that a child that she bears and raises is, in fact, genetically her own. Fathers, however, can’t be quite so sure. Even if “dad” engages in vigilant mate guarding, there’s always the possibility that his partner snuck off for some horizontal mambo action with another guy. Evolutionary psychologists call this the “paternal certainty problem”— men who have been cuckolded and are unknowingly raising a child that’s not their own have failed, from an evolutionary perspective, at passing on their genes. And it turns out that a significant number of men have failed to solve this problem. Think this doesn’t happen? Well, rates of non-paternity have been reported to be as high as 10%,1 although a more realistic estimate is somewhere in the 2-3% range.2 So, if you line up 100 dads and “their” kids in a room, chances are that 2 or 3 of the dads are standing with some other guy’s kid.
If a man can’t always be sure that “his” child is in fact his, what clues might he use to feel a bit more confident in his baby-daddy status? First, men monitor their mates’ behavior and tend to become especially upset at thought of their girlfriends/wives cheating. Clearly, no one likes the idea of their partners getting it on with someone else (cuckold fetishes aside, but we’ll save that for another post), but men are especially bothered by sexual infidelity compared to women and relative to emotional infidelity (i.e., falling in love with someone else).3
Second, “dad” can size-up the baby and see if it looks like him. In one seminal (no pun intended) study, raters were more likely to correctly match pictures of infants with biological fathers than biological mothers (i.e., babies looked more like dad than mom);4 however, this finding has not been replicated by subsequent research.5,6 Interestingly, dads who think their kids look like them tend to have more positive relationships with those children.7 It makes sense that mothers (and mothers’ relatives) are more likely to say that a baby looks like the father, possibly as a form of reassuring the father of his paternity.8 Although, to be fair, there is just something about a bald chubby baby that looks more “dad-like” than “mom-like.”
Clearly, men are concerned with their biological relatedness to their (supposed) children, and adaptive mechanisms to reassure them of their fatherhood may have evolved. But there is still plenty of paternity confusion going on in relationships, as evidenced by the never-ending supply of drama on the Jerry Springer show.
Sponsored: What about paternity testing?
The only way of being sure of whether you are the real daddy is by doing a home paternity test. This DNA test is simple to carry out: The father in doubt needs to find an online company offering such tests and request a DNA sampling kit. Once he receives the kit he will need to use the swabs within to collect DNA samples from himself and the child. The ease of collecting samples with oral swabs makes them ideal for such a test. All that needs to be done is rub the swabs under the tongue and against the cheek for a couples of seconds and then left to dry. Once dry, they need to be sent back for laboratory analysis.
Perhaps some fathers wish to do the test a bit more discretely than with oral swabs! Well this too would not be a problem as many companies offer alternative types of DNA samples that can be used for paternity testing: used Kleenexes, blood stains, nail clippings, teeth and the list goes on and on. As to the results, the most important part of the test: if the dad tested is the real father, the result will show a percentage probability of 99.9% or higher. If he is not the daddy of the child, then this probability will be 0%.
Until next time, take care of yourself…and each other.
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1MacIntyre, S., & Sooman, A. (1991). Nonpaternity and prenatal genetic screening. Lancet, 338, 869-871.
2Anderson, K. G. (2006). How well does paternity confidence match actual paternity? Evidence from worldwide nonpaternity rates. Current Anthropology, 47, 513-520.
3Buunk, B. P., Angleitner, A., Oubaid, V., & Buss, D. M. (1996). Sex differences in jealousy in evolutionary and cultural perspective: Tests from the Netherlands, Germany, and the United States. Psychological Science, 7, 359-363.
4Christenfeld, N. J. S., & Hill, E. A. (1995). Whose baby are you? Nature, 378, 669.
5Brédart, S., & French, R. (1999). Do babies resemble their fathers more than their mothers? A failure to replicate Christenfeld and Hill. Evolution and Human Behavior, 20, 129-135.
6Alvergne A., Faurie, C., & Raymond, M. (2007). Differential facial resemblance of young children to their parents: Who do children look like more? Evolution and Human Behavior, 28, 135-144.
7Burch, R. L., & Gallup, G. G. Jr. (2000). Perceptions of paternal resemblance predict family violence. Evolution and Human Behavior 21, 429-435.
8Daly, M., & Wilson, M. I. (1982). Whom are newborn babies said to resemble? Ethology and Sociobiology, 3, 69-78.
Dr. Benjamin Le – Science of Relationships articles | Website/CV
Dr. Le’s research focuses on commitment, including the factors associated with commitment and its role in promoting maintenance. He has published on the topics of breakup, geographic separation, infidelity, social networks, cognition, and need fulfillment and emotions in relationships. 
Robert says
This article uses a lot of offensive, old fashioned, outdated terms. Poor choice of words like "his own," "real father," and "…If he is not the daddy of the child…" are incredibly offensive to adoptive children and parents. Terms such as "biological father," "bio dad," etc. are more precise and better describe what you are talking about rather than "real father." What is a real father, anyway? As an adoptive father, am I not real? Although I am not genetically related to my adopted children, they are very real and so am I. You can't get any more real than parenting all day and all night through sickness, crisis and hospital stays. The relationship is real. The love is real. Genetic relatedness does not define real.
This author does an incredibly poor job writing under the heading of "Science of Relationships." The terms used in this piece (real father, etc.) are utter junk science. This piece, were it to focus on the SCIENCE of RELATIONSHIPS would recognize that parents who are not biologically related to their children are, in fact, real parents.
The studies discussed in this piece are very interesting. They deserve much better treatment than the sloppy and offensive piece written by this particular author. What a disappointment. Fail.
Science of Relationships says
The term "real daddy" is in the advertising on the page, not in the article. I think the text of the article (above the sponsored ad) is pretty clear in talking about genetic relatedness and specifically those non-biologically related men who are unknowingly investing in children that they are not genetically related to. Nothing here is not discounting the important parenting contributions of (non-biologically related) fathers.