Download EP Haidt 9

Chapt 9. Why are we so Groupish?
To this point, Haidt’s portrait of human nature somewhat
cynical – Glaucon: we care more about looking good
than being good.
“I do believe that you can understand most about moral
psychology by viewing it as a form of enlightened selfinterest”.
We may be altruistic, but we are strategically altruistic,
not universally altruistic.
If moral psychology is fundamentally selfish then, it can be
explained by natural selection working at the level of
the individual.
Chapt 9. Why are we so Groupish?
But this portrait is incomplete: we are also groupish.
Although some mental modules designed to further our
own selfish interests, others are designed to further our
group’s interests (perhaps at a cost to ourselves).
“We are not saints, but we are sometimes good team
players”.
“Do we have groupish mechanisms…because groups that
succeeded in coalescing and cooperating outcompeted
groups that couldn’t get it together? If so, then I’m
invoking a process known as ‘group selection’, and
group selection was banished as a heresy from
scientific circles in the 1970’s”.
Chapt 9. Why are we so Groupish?
Haidt argues that “group selection was falsely convicted
and unfairly banished”.
Chapter plan: to present four pieces of new evidence that
he believes “exonerate group selection (in some but not
all forms)”.
The new evidence demonstrates the value of thinking
about groups as real entities that compete with each
other.”
“Evidence leads directly to the third and final principle of
moral psychology: Morality binds and blinds”.
Chapt 9. Why are we so Groupish?
Haidt: “human nature mostly selfish, but with a groupish
overlay that resulted from the fact that natural selection
works at multiple levels simultaneously ”.
Individuals compete with individuals within groups – which
favors selfishness (including strategic cooperation),
Groups compete with groups – between group competition
favors true team players.
“These two processes [individual-level and group-level
selection] pushed human nature in different directions
and gave us the strange mix of selfishness and
selflessness that we know today”.
Chapt 9. Why are we so Groupish?
Haidt: “A gene for suicidal self-sacrifice would be favored
by group-level selection (it would help the team win),
but it would be so strongly opposed by selection at the
individual level that such a trait could evolve only species
such as bees, where competition within the hive has
been nearly eliminated and almost all selection is group
selection13”.
Footnote 13: Bees “perfectly consistent with inclusive
fitness theory … but [some] people who work with bees,
ants [etc.] sometimes say that multilevel selection helps
them see phenomena that are less visible when they
take the gene’s eye view”.
A different language…
Chapt 9. Why are we so Groupish?
Most groupish groups fare best. But how did early humans
get these groupish abilities? According to Darwin:
1. Social instincts (hang with the group)
2. Reciprocity
3. Concern with reputation (Glaucon) – the moral
sentiments sense of shame and love of glory evolved
by individual-level selection
4. Capacity to treat duties and principles as sacred
(part of our religious nature)
Free-riding no longer so attractive. Group-level selection
now becomes more potent. Groups now outcompete –
and replace – other groups.
“In 1955, a young biologist named George Williams attended a lecture at the
University of Chicago by a termite specialist. The speaker claimed that many
animals are cooperative and helpful, just like termites. He said that old age and
death are the way that nature makes room for the younger and fitter members of
each species. But Williams was well versed in genetics and evolution, and he was
repulsed by the speaker’s Panglossian mushiness. He saw that animals are not
going to die to benefit others, except in very special circumstances such as those
that prevail in a termite nest (where all are sisters). He set out to write a book that
would “purge biology” of such sloppy thinking once and for all.
In Adaptation and Natural Selection (1966), Williams told biologists how to think
clearly about adaptation. He saw natural selection as a design process. There’s no
conscious or intelligent designer, but Williams found the language of design useful
nonetheless. For example, wings can only be understood as biological mechanisms
‘designed’ to produce flight. Williams noted that adaptation at a given level always
implies a selection (design) process operating at that level, and he warned readers
not to look to higher levels (such as groups) when selection effects at lower levels
(such as individuals) can fully explain the trait…
… A fast herd of deer is nothing more than a herd of fast deer”.
Chapt 9. Why are we so Groupish?
Willliams: Morality is “an accidental capability produced, in
its boundless stupidity, by a biological process that is
normally opposed to the expression of such a capability”.
Haidt: “Group selection is controversial among
evolutionary theorists, most of whom still agree with
Williams that group selection never actually happened
among humans. They think that anything that looks like a
group-related adaptation will—if you look closely
enough—turn out to be an adaptation for helping
individuals outcompete their neighbors within the same
group, not an adaptation for helping groups outcompete
other groups.
Chapt 9. Why are we so Groupish?
Evidence for Group Selection*(Exhibits):
A. Major Transitions
B. Shared Intentionality
Tomasello: you’ll never see 2 chimps carrying a log
C. Genes and Cultures Co-evolve
D. Evolution can be Fast
Lactose tolerance as example of C and D
Belayev’s foxes as example of D
*for group-related adaptations
Chapt 9. Why are we so Groupish?
Evolution can be Fast
Belayev’s foxes
http://www.youtube.com/watch?v=ZEOjlsUd7j8
Lactose Intolerance
Mammals stop drinking milk at weaning. They also stop producing
lactase, the digestive enzyme that breaks down lactose (the main
carbohydrate in milk) into glucose and galactose (sugars that are
easily absorbed in the bloodstream and provide energy). Cessation
of both lactase production and milk drinking characterizes most
human populations, especially those of African and Asian descent.
In the majority of non-European populations, fresh milk is
considered an unpleasant substance to be consumed only as a last
resort. Lactose intolerance is the rule, and it is now clear that
lactose tolerant Europeans are atypical among humans (as well as
among all mammals).
Why do some humans, however, retain the ability to digest lactose?
A genetic mutation that maintains lactase production into
adulthood occurs among certain populations that practiced cattle
domestication. These individuals have the lactase persistence trait.
LM = lactose
malabsorption
Bloom & Sherman 2005
Masai – Kenya
When nutrient rich nonhuman milk became widely available in
pastoralist societies, the rare genetic variations that allowed some
adults to easily digest lactose were selected for and this trait
became more common.
Lactase persistence genes that have evolved in Africa have evolved
independently of the gene variants predominant in Europe.
% of Population
Lactose Tolerant
Age of
Gene
Age of
Domestication
of Cattle
West
Africa
5 to 20%
6000 to 7000
years ago
7700 to 9000
years ago
East
Africa
26 to 88 %
2700 to 6800
years ago
3300 to 4500
years ago
Southern
Europe
50%
8000 to 9000
years ago
8000 years
ago
Northern
Europe
90%
2000 to 20,000
years ago
8000 years
ago
Region
Chapt 9. Why are we so Groupish?
“Group-related adaptation” (= ?) requires group selection,
i.e., this adaption may be disfavored within the group, but
groups with this adaptation fare better than groups
without it. Altruists suffer within the group, but groups
with altruists outcompete groups without altruists.
Note: ‘group selection’ (or ‘multi-level selection’) refers to
selection on gene-based traits.
Two problems:
1. Is group selection different from kin selection?
2. Is the group selection Haidt is talking about truly
genetic selection?
It has since been shown that kin selection and new group selection
are just different ways of conceptualizing the same evolutionary
process. They are mathematically identical, and hence are both valid
(references). New group selection models show that cooperation is
favoured when the response to between group selection outweighs
the response to within-group selection, but it is straightforward to
recover Hamilton’s Rule from this. Both approaches tell us that
increasing the group benefits and reducing the individual cost
favours cooperation. Similarly, group selection tells us that
cooperation is favoured if we increase the proportion of genetic
variance that is between-group as opposed to within-group, but that
is exactly equivalent to saying that the kin selection coefficient of
relatedness is increased (references). In all cases where both
methods have been used to look at the same problem, they give
identical results (references).
West, Griffin & Gardner (2007) Social semantics: altruism, cooperation, mutalism, strong
reciprocity and group selection. Journal of Evolutionary Biology, 20: 415-432
Chapt 9. Why are we so Groupish?
“Group-related adaptation” (= ?) requires group selection,
i.e., this adaption may be disfavored within the group, but
groups with this adaptation fare better than groups
without it. Altruists suffer within the group, but groups
with altruists outcompete groups without altruists.
Problem 2: is group selection here really genetic selection?
Cultural selection is a strong form of group selection that it
is not gene-based. Good ideas concerning making tools,
making foods, avoiding poisons, keeping young alive,
fighting, etc., will spread with dispersal of individuals with
this knowledge into new groups. It’s not genes that are
selected, but the ideas (memes).
The gene-based traits that are selected are:
intelligence, creativity, learning & teaching,moral intuitions.
It has since been shown that kin selection and new group selection
are just different ways of conceptualizing the same evolutionary
process. They are mathematically identical, and hence are both valid
(Hamilton, 1975; Grafen, 1984; Wade, 1985; Frank, 1986a, 1998;
Taylor, 1990; Queller, 1992; Bourke & Franks, 1995; Gardner et al.,
2007). New group selection models show that cooperation is
favoured when the response to between group selection outweighs
the response to within-group selection, but it is straightforward to
recover Hamilton’s rule from this. Both approaches tell us that
increasing the group benefits and reducing the individual cost
favours cooperation. Similarly, group selection tells us that
cooperation is favoured if we increase the proportion of genetic
variance that is between-group as opposed to within-group, but that
is exactly equivalent to saying that the kin selection coefficient of
relatedness is increased (Frank, 1995a). In all cases where
both methods have been used to look at the same problem, they
give identical results (Frank, 1986a; Bourke & Franks, 1995;
Wenseleers et al., 2004; Gardner et al., 2007).
It’s Not All About War
“I’ve presented group selection so far in its simplest possible form: groups
compete with each other as if they were individual organisms, and the most
cohesive groups wipe out and replace the less cohesive ones during intertribal
warfare. That’s the way that Darwin first imagined it. But … Lesley Newson points
out:
I think it is important not to give readers the impression that
groups competing necessarily meant groups being at war or
fighting with one another. They were competing to be the most
efficient at turning resources into offspring. Don’t forget that
women and children were also very important members of
these groups.
Of course she’s right. Group selection does not require war or violence. Whatever
traits make a group more efficient at procuring food and turning it into children
makes that group more fit than its neighbors. Group selection pulls for
cooperation, for the ability to suppress antisocial behavior and to spur individuals
to act in ways that benefit their groups. Group-serving behaviors sometimes
impose a terrible cost on outsiders (as in warfare). But in general, groupishness is
focused on improving the welfare of the ingroup, not on harming an out-group.