I have difficulty thinking of Aristotle as a blank slate
theorist. The view that evolved psychological adaptations play no role in
determining human behavior seems impossible to reconcile with Aristotle’s teleological
view that living entities contain in themselves the principle of their own
development. It is worth remembering, however, that Aristotle saw personal
development as linked to formation of good habits – he saw roles for both nature
and nurture in human flourishing. In order to make sense of the passage quoted
above I need to allow myself to imagine a blank writing tablet that has
functional specialization allowing information relevant to the flourishing of our
pre-historic ancestors to be most readily written upon it. (Incidentally, the
quote is from On the Soul, Book III, Part 4.)
Evolutionary psychology has promoted the view that evolved
psychological adaptations play a role in determining human behavior. To
consider the light it sheds on the source of human intuitions I will begin with
Steven Pinker’s list of the cognitive intuitions (also referred to as modules, systems,
stances, faculties, mental organs, multiple intelligences, and reasoning engines),
and then move on to Jonathan Haidt’s list of ethical intuitions. I will then
consider whether attacks on evolutionary psychology should cause us to be wary
of the evolutionary reasoning associated with such lists.
Pinker suggests that we are equipped with a range of different
cognitive intuitions that evolved through psychological adaptations to keep our
ancestors in touch with reality. These intuitions emerge early in life, and are
present in every normal person. His list includes a basic intuitive grasp of physics,
biology, engineering, psychology, and economic exchange. It includes a spatial
sense, and senses of number and probability. It also includes language, and a
mental data base and logic that are used to represent ideas and infer new ideas
from old ones. These intuitions are suitable for the lifestyles of small groups
of illiterate people living several thousands of years ago. They do not give people a spontaneous intuitive understanding of modern
science, technology, or economics. (Steven Pinker, The Blank Slate, 2002,
219-21)
Haidt argues that moral intuitions evolved to meet various
adaptive challenges faced by our ancestors. He suggests that moral intuitions
relating to care and harm evolved to protect children; intuitions relating to
fairness and cheating evolved to reap benefits of cooperation; intuitions
relating to loyalty and betrayal evolved to protect groups from challenges;
intuitions relating to authority and subversion evolved to obtain benefits from
hierarchies; and intuitions about sanctity and degradation evolved to avoid
contamination and disease. (Jonathan Haidt, The Righteous Mind, 2012, 123-127)
The views of Pinker and Haidt seem to me to be plausible,
but can this kind of reasoning withstand the criticism that evolutionary
psychology consists of “just so” stories?
In his book, Rethinking Evolutionary Psychology, Andrew Goldfinch, a philosopher, tells readers that critics view evolutionary psychology explanations “as shockingly naked in historic and scientific detail”. Massive modularity has been a particular focus of criticism. The strongest form of massive modularity claims that there are no systems or mechanisms that are not dedicated to particular problems.
I came to Goldfinch’s book with the idea that the concept of
brain plasticity was opposed to modularity. I had thought that evidence that
brains “rewire” themselves in response to experience as people transition from
infancy to adulthood would tend to count against modularity. However, many cognitive
psychologists stress that when they talk about modules what they have in mind
is functional specialization which is consistent with overlap between
processing areas of the brain. Plasticity enables brains to develop so that
individuals normally have intuitions that are common among adult humans.
However, Goldfinch also makes it clear that the existence of
innate knowledge does not require massive modularity. It is possible for
domain-specific knowledge to be generated by domain-general processing. Both
domain-specific and domain-general mechanisms are compatible with evolutionary
theory. I think it follows that the issue of whether the lists of intuitions
compiled by Pinker and Haidt are evolutionary adaptations does not depend on
the validity of the theory of massive modularity.
The main point that Goldfinch makes is that leading evolutionary
psychologists have brought their research program into disrepute by packaging it as
a paradigm shift. The research program became identified with claims of a strong
form of massive modularity as leading proponents argued that evolutionary
adaptation implies the existence of strong massive modularity. Leading proponents
used the concept of strong massive modularity to challenge conventional social
science based on the foundation of domain-general knowledge and processes that
are exclusively social. This prompted excessively critical responses that
sought to discredit the entire research program as “just so” stories.
Goldfinch argues that strong massive modularity is not
integral to evolutionary psychology. He suggests that evolutionary psychology should
be viewed as an exploratory research program aimed at generating and testing
hypotheses about psychological mechanisms. Viewed in that light, evolutionary
psychology explores whether psychological traits that are observed across
cultures could be adaptations, and has potential to guide researchers into identifying
new behavioral patterns and mechanisms.
Goldfinch summarizes his view as follows:
“Initial evolutionary psychology hypotheses aim, or should
aim, not for the last evolutionary word on a given phenomenon, but the first.
They are in constant adjustment—both with the research programme’s own findings
and findings from adjacent research programmes and disciplines. If this is
done, this should generate sophisticated hypotheses, as well as generate
progressive increments to our understanding of psychological and social
phenomena.” (200)
I can see the wisdom in Goldfinch’s suggestion that
evolutionary psychologists should not be aiming to have the last word. Should
any scientist ever be aiming to have the last word? However, I think it is
inevitable that a good number of the hypotheses advanced by evolutionary
psychologists will challenge beliefs that human behavior is wholly attributable
to simple mechanisms of learning and can be modified readily by changing social
arrangements.
Even if the views about human intuitions put forward by evolutionary
psychologists only have the status of plausible speculations, they can still help
us to comprehend aspects of the world we live in. For example, Pinker’s views provide
a provisional understanding of why people tend to perceive the world they live in
much the same way as their ancestors who knew nothing about the processes that
modern physics describes. Haidt’s views provide a provisional understanding of why
people hold ethical intuitions that cannot be readily explained in terms of
current social circumstances. The paucity of historic detail supporting such speculations
should not cause them to be dismissed unless more plausible explanations are
offered. Those seeking truth should find plausible speculations more satisfying
than implausible speculations and mysteries.