Finnish Type A personalities have more offspring

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Adolescent Leadership and Adulthood Fertility: Revisiting the “Central Theoretical Problem of Human Sociobiology”:

Human motivation for social status may reflect an evolved psychological adaptation that increased individual reproductive success in the evolutionary past. However, the association between status striving and reproduction in contemporary humans is unclear. It may be hypothesized that personality traits related to status achievement increase fertility even if modern indicators of socioeconomic status do not. We examined whether four subcomponents of type-A personality-leadership, hard-driving, eagerness, and aggressiveness—assessed at the age of 12 to 21 years predicted the likelihood of having children by the age of 39 in a population-based sample of Finnish women and men (N=1,313). Survival analyses indicated that high adolescent leadership increased adulthood fertility in men and women, independently of education level and urbanicity of residence. The findings suggest that personality determinants of status achievement may predict increased reproductive success in contemporary humans.

In Finland a “Type-A Personality” presumably refers to someone willing to make eye contact with family members. In any case I think this table is probably the most informative:

The main caveat which is stated in the paper is that we’re talking about Finland today. How generalizable is this? If leadership was a primary factor behind reproductive success over long periods of time how come we’re not all Type A personalities? I think it seems likely that the fitness of these individuals and their morph exhibits frequency dependence. Additionally the longer term volatility of this strategy probably differs from more retiring personal profiles. The Type A strategy seems more likely to be subject to winner-take-all dynamics; there were many prominent leaders on the Mongolian plain of 1250. Very few of them have descendants due to the fact that one Type A eliminated all the rest. In Farewell to Alms Greg Clark reports data which illustrate that before the 19th century the blooded military nobility might have had below average replacement because of morality during war. In contrast, the gentry were fertile. Not to nerd out, but this shows that the Hobbit strategy can beat the Numenorean over the long term. Modern post-industrial societies have a particular social ecology, and are subject to a dynamic contingent upon that ecology. Let’s not overgeneralize.

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16 Comments

  1. What on earth is adolescent leadership? Leading gangs? Skippering a cricket team? (If they played cricket in Finland.) Joining the army as an officer cadet? Being promoted in the boy scouts? I’m a wee bit flummoxed.

  2. the paper is open access. perhaps reading it will calm you down.

  3. NERD

  4. The correlation is stronger for women than for men. Does that mean men are attracted to powerful women? Woo-hoo! Sarah Palin and Hillary Clinton!

  5. Har de har har. I’m a Type B Swedish American, and not only do I make eye contact with family members, I even make it with strangers if I steel myself and take a deep breath first! 
     
    I bought three shirts at a department store today, and I made a point of making eye contact with the clerk as he finished the transaction. I tried to smile as well but I may have just grimaced uncomfortably. This is Seattle so he’s probably used to it.

  6. finns make swedes look like italians. most of ‘finnish’ history is about swedes leading them. often to their deaths in the service of the swedish nation :-) (30 years war, great northern war, etc.)

  7. The correlation is stronger for women than for men. Does that mean men are attracted to powerful women? 
     
    My guess: There are longer tails to the male distribution.

  8. The correlation is stronger for women than for men. Does that mean men are attracted to powerful women? 
     
    men don’t have to be the causal agents here. e.g., it may be that stronger willed women who want more children find it easier to coerce reluctant men.

  9. “the paper is open access”: not to me – I am under instruction not to accept cookies.

  10. The stronger correlation for women may be an artifact of the age cutoff they used (39 years). Women will be 90% done having kids by then; some men could just be getting started, and certainly on average men are going to have a larger proportion of their kids after the age of 39.

  11. Haha. Are Finnish culture even shier than East Asians like Japanese?

  12. Bio, I’m told that being promoted in the boy scouts is not positively correlated with an increase in reproductive success. 
     
    I wouldn’t know, my parents couldn’t afford the uniform and the pocket knife with the thing for getting stones out of horses’ hooves, but it didn’t prevent me from reproducing. I just avoided eye contact during the act.

  13. Modern progressive society are reverting back to hunter-gather life style with free competition for mates instead of domesticated breeding (arranged marriage) for most part of agricultural civilization. Different enviroment favor different personality or genes.

  14. Boxenhorn, razib: 
     
    Aren’t those just different ways of saying that most men’ll plug anything that walks?

  15. Sandgroper: 
     
    Way to go! But a bit of old-timey practical advice here: sneak a peek! If her eyes are open, either she wants eye contact–or you’re doin’ sumpn wrong.

  16. This study reminded me of another based on military records from WWI showing that men who had more than four children before age 30 were far more likely to live to 100 than men who didn’t. 
     
    This is the address for the story about the study. I didn’t get to read the actual study. 
     
    http://www.washingtonpost.com/wp-dyn/content/article/2007/11/19/AR2007111900560.html

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