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Thursday, September 29, 2011

Evolutionary Psychology: Vacuous or False?

J.B.S. Haldane famously quipped that "I would lay down my life for two brothers or eight cousins." If this simple mathematical relationship really captures the essence of altruism, then we should find that people are just as willing, on average, to lay down their life for their sibling as for their child. Of course, that is obviously false. What we are left with is studies showing that foraging robots obey the relationship! So, what is true about evolutionary psychology (in this regard) has been known for a long time: "Blood is thicker than water" and so on. What is novel about it is falsified with about a minute's thought.

6 comments:

  1. I believe that law is one of those "ceteris paribus" ones -- but all else isn't equal for a parent w/r/t a child vs. a sibling; the former will generally be more likely to promote the parent's inclusive genetic fitness due to greature future reproductive capacity. Simliarly, parents share the same gene fraction with each child, but do indeed play favorites ... and not suprisingly, their mechanism for thereby choosing correlates tremendously well with what factors influenced the spreading of genes back on the savannah.

    (Indeed, per Darwinian theories, it couldn't be any other way: since it is the genes that replicate, genes in individuals that don't have preferences to act in accordance with that law will be dominated by the [better-reproducing] genes in those who do.)

    In exactly the same manner, eusocial insects share a greater fraction of genes with one another and therefore are more self-sacrificial for the sake of the colony than humans are for a human "colony". And then, even they are dwarfed by the altruism shown by the cells within an animal, which have a 100% genetic match, and, not surprisingly, are even more frequently found to sacrifice themselves for the sake of the "colony" (the animal).

    Evolution theorists aren't stupid, and have long considered these obvious objections.

    Also, if you really think EvoPsych is vacuous or wrong, can you answer my my question about the non-EvoPsych way that you would have predicted the two empircal regularities I mentioned?

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  2. So, as I said, we are left with the truism that genes matter. Of course they do.

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  3. 'the former will generally be more likely to promote the parent's inclusive genetic fitness due to greater future reproductive capacity."

    OK, Silas, let's say a known-to-be sterile child and a wildly reproductive brother are both drowning: who does the Mom on the river bank save? Nine times out of ten, the kid, who will never reproduce.

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  4. So, as I said, we are left with the truism that genes matter. Of course they do.

    No, we're not left with just that, and no, that (the sense in which genes interplay with psychology) wasn't obvious for most of history.

    OK, Silas, let's say a known-to-be sterile child and a wildly reproductive brother are both drowning: who does the Mom on the river bank save? Nine times out of ten, the kid, who will never reproduce.

    That experience was not common in the ancestral environment, so we should not expect to have mechanisms sensitive to its effect on inclusive genetic fitness; selection effects wouldn't be precise enough to identify the genetic merit in such a tradeoff. The rule still holds in general, it's just loaded down with a lot of caveats, as is typical for special-case simplifcation of a more fundamental regularity.

    So you found that a statistical phenomenon has exceptions. Is that supposed to somehow be some damning indictment of a scientific claim?

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  5. The explanation among evolutionary psychologists is that there is an incentive for rivalry among siblings to compete for precious resources from parents. The emotions that genes give us aren't precise enough to change our sentiments when we are adults.

    There is also a strong relationship between sentiments towards protecting children and the number of expected children that child would in turn have.

    There is more discussion on each of these points (if memory serves correct) in The Moral Animal by Robert Wright.

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  6. "So you found that a statistical phenomenon has exceptions."

    So, when the statistical law predicts 50%, and the result we find is instead 98%, that's an "exception"?!

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