Nature-v-Nurture is not Stability-v-Instability

“The Psychological Foundations of Culture,” by John Tooby and Leda Cosmides, in The Adapted Mind, Oxford University Press. [notes].

The Origin of Politics: An Evolutionary Theory of Political Behavior,” by John Alford and John Hibbing, Perspectives on Politics, Vol 2. No. 4, December 2004, 707-723 [notes].

“Are Political Orientations Genetically Transmitted?” by John Alford, Carolyn Funk, and John R. Hibbing, American Political Science Association, May 2005, [notes].

The syllabus for Child Psychology calls for a short, interpretive paper over some aspect of the text. I will choose to comment on a paragraph in Chapter 1, under the heading “Relative Influence of Nature and Nurture?”

Berk states on page nine(references excluded)

A theory’s potential on the roles of nature and nurture affects how it explains individual differences. Some theorists emphasize stability — that children who are high or low in a characteristic (such as verbal ability, anxiety, or sociability) will remain so at later ages. These theorists typically stress the importance of heredity. If they regard environment as important they usually point to early experiences as establishing a lifelong pattern of behavior. Powerful negative events in the first few years, they argue, cannot be fully overcome by later, more positive ones. Other theorists are more optimistic. They believe that change is possible and likely if new experiences support it.

While I generally admire the author’s balanced view of the nature-nurture controversy, I believe this paragraph is confused. Prominent nature-oriented perspectives have emphasized early learning and stability. Sigmud Freud, for example, believed that psyhosexual development in early childhood can have lasting impact (Berk 17), while even Jean Piaget emphasized that an early childhood passage through the sensorimotor stage was necessary for success concrete and formal operations (21). Under either Freud or Piaget, a child’s maladaptiosn early in life will cascade into problems later on. At the same time, proponents of genetic influences attack the idea that traits must be stable throughout life. “Just as teeth or breasts are absent at birth, and yet appear through maturation,” the founders of Evolutionary Psychology write, “evolved psychological mechanisms… could develop at any point in the life cycle.” (Tooby and Cosmides 10). Likewise, a researcher working at the University of Nebraska – Lincoln discovered that the influence from socialization on many aspects of personality plummets during life (Alford and Hibbing 2004; Alford, Funk and Hibbing 2005). Under any of this “nature”-oriented research, “stability” is called into question if not attacked.

The precise role of nature and nurture is unknown, but the issue is larger than just “stability.”

3 thoughts on “Nature-v-Nurture is not Stability-v-Instability”

  1. this issue was settled for me by having twins. though their nurture has been very similiar (they are boy-girl, so it might have been a little variation), their natures are very different.

  2. Sean, one interesting finding is that the closer the contact between twins, the more different their natures. (So that while the genetic correlation is positive, the environmental one can actually be negative.)

    The developmental program, in some culture without traumatic events, seems pretty fixed. Twins differentiate themselves from each other if they are in regular contact, but otherwise they will “naturally” lead even more similar lives.

    (My parents tell the story of how I was kicked out of the newborn wing, and into the hallway, because I was crying to loudly and preventing other newborns from sleeping. A foreshadowing of agit-blogging to come???)

  3. “The precise role of nature and nurture is known …”

    Is it, begad! To what degree of precision exactly? 0.1? 0.001?

    Seriously, the way you've quoted C & T makes it sound like they think that :

    – behavioural trait X is due to come online at time t(n) and nothing that happens at time t(n-1) is likely to perturb or inhibit it. (Presumably because of some kind of self-organization / resilience in the developmental process.)

    However, as far as I can see, what they're actually saying is merely that :

    – the fact that trait X wasn't *visible* at time t(n-1) doesn't mean that it arrived at time t(n) due to some environmental influence. It might have been latent; genetically programmed to come online only at the appropriate age.

    That's a far weaker statement than yours about early problems leading to cascading failure later in life.

  4. wow, Dan. that's fascinating. makes good sense of the many studies of separately adopted twins who grow up to be so similar.

    but i still stand by their natures being very different from early on, before they could have influenced one another much at all.

    to say nothing of the fundamental genetic differences among fraternal twins compared with identical…

  5. Phil,

    Eep! It should be “is not known…” 🙂

    My thrust (which was obscured by that typo) is not that Berk is 100% wrong, but just confused. Piaget and EP both focus on development, for instance, and one isn't more focused on negative events than the other. Nor is one necessarily more focused on stability of personality than the other. (Indeed, genetic factors incorporates two very different perspectives, Evolutionary Psychology and Behavioral Genetics, and environmental determinism incorporates most every widespread social science theory.)

    There are other problems in the passage too. There is a genetic factor in how people respond to major tragedy, with some people unaffected, some people slightly affected, and others often fatally affected. So it isn't' that hereditarians are somehow uniquely focused on traumatic events.

    Likewise, the claim that environment is important only in establishing a lifelong pattern to people who study genetic factors is bizarre. I mentioned how Freud (an environmental determinist) believed exactly that. Tooby and Cosmides, the founders of Evolutionary Psychology, would say that environment is important for what actions it “evokes” at any given time. The paragraph just doesn't make sense. It should be scrapped.


    Cool! I agree completely — just sharing an anecdote, didn't mean to contradict you. 🙂 Meaningful preference differences have been statistically shown in populations as young as one day old, so I am not doubting you at all.

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