Chapt 9 . Why are we so G roupish?

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 self-interest”.

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.


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”.

But this portrait is incomplete:


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”.


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”.


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…


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. Reciprocity3. 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”.


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.


Evidence for Group Selection (Exhibits):

A. Major Transitions

B. Shared Intentionality

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

Tomasello: you’ll never see 2 chimps carrying a log

* for group-related adaptations

*


Evolution can be Fast

Belayev’s foxes

http://www.youtube.com/watch?v=ZEOjlsUd7j8



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.

Lactose Intolerance

LM = lactose malabsorption

Bloom & Sherman 2005

Masai – Kenya

Region% of Population Lactose Tolerant

Age of Gene

Age of Domestication

of Cattle

West Africa 5 to 20% 6000 to 7000

years ago7700 to 9000

years ago

East Africa 26 to 88 % 2700 to 6800

years ago3300 to 4500

years ago

Southern Europe 50% 8000 to 9000

years ago8000 years

ago

Northern Europe 90% 2000 to 20,000

years ago8000 years

ago

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.


“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.

Chapt 9 . Why are we so G roupish?

Documents

Transcript of Chapt 9 . Why are we so G roupish?