In this post, I am referring to this paper:
Jensen, S., & Kirkegaard, E. O. W. (2023). Predictors of engaging in interracial dating. Mankind Quarterly, 64(2), 315–346. https://doi.org/10.46469/mq.2023.64.2.8
Research suggests that mixed-race adolescents are more likely than monoracial adolescents to use drugs or engage in violent behavior, and that interracial relationships contain more conflict than monoracial ones. However, it is not clear whether these outcomes are caused by racial conflict and identity or by self-selection. To determine this, we used data from the NLSY97 and Add Health datasets to explore what characteristics predict whether an individual is engaged in an interracial relationship.
Our investigation suggests that assortative mating occurs between races, where individuals who date individuals of other races tend to be more similar to them. The standardized difference in intelligence between those interracially mated and those who didn’t varied by race (White d = -0.22, p < .001; Black d = 0.31, p < .001; Hispanic d = 0.73, p < .001). Also, there is a difference in height between Hispanics who interracially dated and those who didn’t (mean d = 0.29, p < .001). Interracial daters tended to engage in a broader range of risk-taking behaviors (White d = 0.18, p < .01; Black d = 0.42, p < .01; Hispanic d = 0.53, p < .001) regardless of their race. The available evidence supports that the behavior of mixed-race adolescents is a product of genetic transmission, and that some of the increased divorce and inter-partner violence observed within interracial relationships may be a product of self-selection instead of racial conflict or social pressure.
Most notable result from the paper:
What are the social implications of this study?
Most of the current literature supports two findings regarding interracial dating:
Interracial relationships are more likely to end or have domestic violence issues relative to monoracial relationships, even relationships that involve two ethnic minorities.
Mixed-race children are more likely to have mental/behavioural issues.
Previous researchers blamed social factors for these effects, but they are more likely to be due to self-selection. People who are already mentally/behaviourally divergent get into interracial relationships, and then those relationships are more likely to end. When they have children, because psychological traits are partially heritable, those children are also more likely to be mentally/behaviourally divergent.
One of the reasons that people have traditionally opposed miscegenation is that it reduces the amount of cognitive elites, because it will decrease assortative mating for phenotypes, which increases trait variance. The fact that people assortatively mate for IQ between races (e.g. Whites who date outside their race are slightly dumber, while Blacks/Hispanics who date outside their race are more intelligent) makes this somewhat less of a concern. Also, embryo selection and genetic editing will allow a cognitive elite to exist even with the pressures of dysgenic fertility and miscegination.
Why didn’t big five personality predict interracial dating?
Probably because our measurements were of low quality.
Is the relationship between having multiple sexual partners and having dated interracially an artefact?
In the add health dataset, I measured interracial dating by coding people who had ever dated interracially as ‘1’ and those who hadn’t as ‘0’, based on measurements from waves 3 and 4. Because of this, people who have more sexual partners could have been more likely to have interracially dated while having the same ‘base probability’ of interracially dating. I tested this theory by changing the coding method, and found that this bias didn’t matter very much.
Why do you use the word ‘miscegenation’ over ‘race mixing’ or ‘interracial dating/mating’?
‘Race mixing’ and ‘interracial mating’ sound weird to me, so I prefer to use thw word ‘miscegenation’ instead. Saying ‘interracial dating’ either gets old or doesn’t apply to some situations, so I need a replacement word.
Endogamous isn’t a word.
That’s right. I made it up.
Why is the paper disorganized in pages 322-325?
I’m not sure. I think I sent a bad file to the typesetter. Hopefully it gets fixed.
Is this paper motivated by hate?
No. Longtime readers of the blog probably know I am half White/Hispanic, and do not oppose interracial dating. Neither does Emil Kirkegaard.
Why did you get such large effects?
I intuited that if people assortatively mated for traits within races, those effects probably applied between races, so members of x race who date members of y race are probably more like members of y race in various ways. I honestly didn’t expect to get effects this large; who would’ve thought that there is an 11 point IQ difference in Hispanics who date outside their race vs inside their race?
What about outbreeding depression? Couldn’t this explained the odd psychology of mixed-race individuals?
I think that these kinds of effects are overstated, particularly for highly polygenic traits such as personality, height and intelligence. Notably, the effect of inbreeding between cousins on IQ is actually surprisingly small, and is only associated with a deficit of about 3 points. Admixture studies suggest that the effect of admixture on IQ is linear, not non-linear, so outbreeding vigor/depression have no effects.
There’s a different paper that found that genetic variance barely correlated with phenotypes at all, and educational attainment and height had a slight negative correlation with genetic variance. Unfortunately, I can’t find the link to the full text, but I remember noticing in their paper that impulsivity/risk taking and genetic heterozygosity did not correlate at all, so outbreeding depression can’t explain why mixed-race children have strange behaviour.
What about Asians?
Their sample size was too small, so I excluded them from the study.
What about effects associated with dating high status races (e.g. Whites, Asians) vs low status races (Hispanics, Blacks)?
I tried testing these effects, and got roughly the same results as the ones I got by coding daters as interracial or endogamous. I remember getting slightly different results for big five personality, but I don’t remember in which direction the effects went.
Is there evidence for assortative mating for mate value or mate value/race exchanges (high mate value Hispanics/Blacks dating low mate value Whites)?
No. Attractiveness was a very weak predictor of interracially dating in all races. Chances are there is an effect in real life, but it’s too small to pick up in the data.
Why did you conduct so many statistical tests?
I glossed over the paper, and I counted about 96 statistical tests in total, which is rather extreme, maybe in the ~99.9th percentile of papers in terms of the amount of statistical testing conducted. Traditionally, conducting too many statistical tests in one paper is frowned upon because it distorts the meaning of the p-values in the paper. Personally, I don’t like it because testing too many theories derails the purpose of the paper and increases the odds of blundering something.
Nevertheless, the actual p-values in the paper are solid. The p-value for the difference in parental education between Hispanics who dated interracially and endogamously was 0.0000000002 in the Add Health dataset, which is almost impossible to find by chance. Within that same dataset, the p-value for the difference in IQ was 0.0003 for Whites and 0.000000001 for Hispanics. It’s virtually impossible for these results to happen by chance, even when a large amount of statistical tests are conducted.
As for the juiciest finding, which was that interracial daters tend to be more mentally and behaviourally divergent (named “risk-taking” in the paper), the p-values were good, but not great. For Whites it was p = 0.009, for Hispanics it was 0.0004, and for Blacks it was 0.004. Finding that interracial daters are more mentally divergent in all 3 races is unlikely to be a mere coincidence. Personally, I would give it a 85% chance that this particular finding replicates in a highly powerful study.
Why did you only use the first sexual partner as a measurement of interracial dating in the NLSY dataset?
For some background, in the NLSY dataset I measured interracial dating by determining what was the race of the first sexual partner they had (most lost it when they were 14-20). In the add health dataset, I measured it by determining whether their main sexual/romantixc partner was of a different race in either waves 3 or 4, when the respondents were about 18-28. There are some advantages to using different measurements - it could pick on more complex patterns, where perhaps interracial dating is not very indicative of psychological traits in teenagers, but is in adults.
Despite these divergents in measurement, the results from both datasets were very similar, particularly for IQ and parental SES/education, the traits that were the most predictive of interracial dating.
NLSY results:
Add Health results:
I have seen a number of couples where Asian women have married white men - note that my observations are only in the college graduate and post graduate environment, and I have run across a number of children from such marriages in my work as well (tech environment). And if you want to get fine grained about it, I am familiar with a lot of Jewish - gentile matches, also successful. In the past, these would have been considered different groups.
This analysis describes my parents and me. My mom is white and my dad is black (in the US American sense) but they are otherwise similar in personality and worldview. Extroverted, impulsive, emotionally and financially, and hate reading. Growing up, interacting with them was like dealing with the same person in two different people. I also have issues with executive function, but more about focus and staying on task and not getting lost in my thoughts, as I tend to keep to myself.
I actually come from a long line of miscegenation. My mom’s mom is Rhineland German x Polish, her dad was Ashkenazi x Prussian, and my dad’s mom is Irish x Amerindian. My dad’s dad was the color of night under the new moon, mostly of subsaharan African descent, but he was a little (a quarter or a sixteenth?) Spanish.