Sunday, December 28, 2014

Morality and Selection - How?

Group, individual, or gene level selection: Which has the best explanatory power for our ‘moral’ emotions?

Mark Sloan 12-27-2014

Charles Darwin proposed group selection to explain how “altruistic” behaviors toward others and self-sacrifice for the group, which could easily be taken to be counterexamples to his theory of evolution, might instead be examples of its explanatory power. He observed that, all else being equal, groups that were more cooperative would out compete less cooperative groups. Selection for more cooperative groups selects for biology that better motivates cooperative behavior (Darwin, 1871) and, though Darwin did not mention it, cultural norms that do the same. Thus, we arrive at the simple and appealing notion that people’s experience of compassion and loyalty and cultural norms such as “Do to others as you would have them do to you” (or variations with the same function in increasing cooperation) are arguably near inevitable products of blind evolution of beings with sufficiently complex brains. And no supernatural deity is required to explain human, or any other species’, “goodness”.

Mark Borrello (2005) described group theory’s subsequent rise and then fall from respectability in the 1960’s (mainly due to a theoretical objection and some bad science from a chief advocate) and its rise again, starting in the 1980’s and now called multilevel selection, which is how I will refer to it here where appropriate.

Steven Pinker and twenty three other respected evolutionists provided an accessible snapshot (Pinker 2012) of the lively state of the unresolved debate on group selection’s proper role in evolutionary science. The diversity of pro and con opinions expressed makes it appear the debate about group selection is not close to over.

However, Pinker’s focus on “altruistic” and “self-sacrifice for the group” behaviors as “what must be explained” was a poor choice for resolving the relative explanatory power of group versus individual and gene level selection perspectives. First, as they are commonly understood, these behaviors can have many explanations which make them insensitive tests for differentiating between hypotheses. Also, these explanations included cultural norms and forces, which divert attention to a secondary issue, group selection’s role in cultural evolution. Finally, Pinker appeared to be taking “altruism” to mean something very close to “biological altruism” (behavior by an individual that increases the lifetime fitness of others while decreasing the lifetime fitness of the actor). If what-must-be-explained is biological altruism, his argument is almost won before he starts. Without the requirement to explain cooperation behavior, the most credible candidate is kin altruism, the obvious choice from the gene level selection perspective.

To avoid these and other problems, future group level selection discussions might be made more fruitful by choosing human cooperation as what-must-be-explained. Also, making certain stipulations will clarify the discussions and avoid other above described problems. I propose the following:

1) Multilevel selection’s explanatory power for biology will be evaluated separately from culture, requiring what-must-be-explained to be chosen to insure only biology is needed to explain it.

2) Multilevel, individual, and gene level selection are different perspectives on (or bookkeeping systems for) the same phenomena. In theory, they might all have the same explanatory power.

3) To be a useful part of an evolutionist’s toolkit, multilevel selection’s perspective must show better explanatory power in practice, meaning ability to more readily produce correct explanations of specific biology.

4) A hypothesis’ “in practice” explanatory power may be inferior to its “in theory” explanatory power.

5) Multilevel selection’s “in practice” explanatory power will ideally be evaluated for multiple phenomena, not just one. Requiring explanation of multiple phenomena increases discriminatory power between alternate hypotheses.

I expect these stipulations would be acceptable to many in the field. If they are not acceptable, perhaps discussions could clarify what will be stipulated and any dissenting opinions.

The biology underlying what makes human beings the amazingly cooperative social animals we are, and arguably the heart of what makes us ‘human’, provides two candidates for what-must-be-explained.

The first candidate is our moral emotions triggered by our moral sense that, in part, motivate unselfishness. For reasons described below, I will here take these to be compassion, loyalty, gratitude, anger, disgust, contempt, shame, guilt, and ‘elevation’. (‘Elevation’ is an emotion encompassing feelings of satisfaction and pride.) Note that the existence of the emotions triggered by our moral sense is not culturally dependent. That is, the existence of these emotions does not vary from culture to culture. Only the circumstances when they are triggered and their intensity with which they are triggered are culturally and individually dependent.

The second “cooperation biology” candidate is the cross-cultural universal set (and therefore likely biological, but not certainly biological) of categories of circumstances which can trigger our moral sense to make one of its near instantaneous judgments (and in turn trigger our ‘moral’ emotions). The most commonly referred to version of Moral Foundations Theory identifies five cross-culturally universal categories: care/harm, fairness/cheating, loyalty/betrayal, authority/subversion, sanctity/degradation (Graham 2012).

Another candidate for what-must-be-explained is the evolution of cancers with their intrinsic complexities of simultaneous cooperation and competition at the cancer’s gene, cell, and cell strain levels in the hostile environment of the patient’s immune system. Due to the specialized knowledge required, such group selection debates would likely be most effective among experts.

However, it may be that such a debate is not needed. Researchers in the field use group selection perspectives as standard practice (Merlo, 2006). It seems unlikely that any debate among those experts would conclude using the group selection perspective is not useful in actual practice.

There are doubtless other candidate biological phenomena that could be useful choices for what-must-be-explained.

The following is an example of how the character of group selection discussions could change if what-must-be-explained was human cooperation and the above stipulations were accepted. In the interest of providing a brief example, I will only compare the “in practice” explanatory power of multilevel and gene selection perspectives for our ‘moral’ emotions, the emotions triggered by our moral sense.

Drawing on many sources, Johnathon Haidt argued moral emotions include compassion, gratitude, anger, disgust, contempt, shame, embarrassment, guilt, and ‘elevation’ (Haidt 2003). I largely agree, but add ‘loyalty’, meaning the emotion that motivates “loyal” behavior, since unselfishness motivated by loyalty is a central part of morality. I prefer the word indignation to anger because “indignation” better captures an emotion that is intrinsically about right and wrong. Also, I would omit the emotion “embarrassment” since embarrassment can be about matters having nothing to do with right and wrong, and shame and guilt adequately convey this category of moral emotions. For these reasons, I will use explanatory power for compassion, loyalty, gratitude, anger, disgust, contempt, shame, guilt, and ‘elevation’ as what-must-be-explained.

If our moral emotions are components of cooperation strategies, what necessary functions are they fulfilling?

Tit-for-tat2 is the simplest highly effective cooperation strategy known in game theory. It seems almost inevitable that, if evolution did encode cooperation strategies in our moral sense, something like tit-for-tat would be one of those strategies. Tit-for-tat has two necessary behavioral components: 1) cooperation by unselfishly risking exploitation in any first interaction and also if the other individual cooperated in the previous interaction and 2) retaliation if the other individual attempted to exploit unselfishness in the previous interaction.

However, this simple tit-for-tat strategy is not always the best, and what is better varies with circumstances. Perhaps sometimes there are ways to predict who is likely to be a good cooperator and who is likely to exploit you – for instance from gossip about other’s interactions with the individual. Perhaps ‘forgiveness’ of an instance of exploitation could avoid cooperation destroying endless cycles of retaliation.

How might evolution most efficiently encode motivation for people to develop more effective variations of tit-for-tat and even switch between them in the many different circumstances encountered over a lifetime, and sometimes even over the course of a single day – as we know people readily do? If a mutation produced a psychological reward for achieving cooperation, then that mutation could be selected for because it motivates the individual to find those strategies that are more effective variations of tit-for-tat and to switch between them according to circumstances.

So if evolution did encode cooperation strategies in our moral sense, the simplest implementation that would be effective in diverse circumstances would have three necessary components: 1) motivation for unselfish behaviors, such as helping actions, which can initiate cooperation but risk exploitation, 2) motivation for retaliation against exploiters, and 3) psychological rewards for achieving cooperation.

This is exactly what we find in our moral emotions. 1) Compassion, loyalty, and gratitude motivate unselfish behaviors that initiate or maintain cooperation. 2) Indignation, disgust, and contempt motivate behaviors that punish other’s exploitation of unselfishness; shame and guilt internally punish our own selfishness. 3) The emotional experience of ‘elevation’ rewards our own successes at cooperation, motivates imitating other’s successes, and encourages staying in cooperative groups and seeking to increase cooperation within those groups.

In contrast, consider the gene level selection perspective’s most common explanation of unselfish behavior toward non-kin (and moral behavior in general): that unselfishness toward non-kin is best explained as a product of kin altruism and cultural influences (Pinker 2012). How well does that explanation explain the existence of our moral emotions?

Kin altruism readily explains the existence of compassion and loyalty toward close kin and the reward of ‘elevation’ for cooperation with close kin. While speculative, the argument that these emotions are triggered toward non-kin due to a kind of error in kin detection is possible.

But what about the other six: gratitude, Indignation, disgust, contempt, shame and guilt? How are these explained by kin altruism? They appear to have nothing to do with kin altruism. I expect clever people can find arguments that all these emotions can be explained by kin altruism. But inventive speculations about how they might be explained as products of kin altruism fall far short on the “best explanation scale” compared to multilevel level perspective’s robust explanation.

Based on relative explanatory power, we can conclude that the majority of our moral emotions are elements of reciprocity cooperation strategies, not kin altruism.

Does this failure to explain our moral emotions mean that gene level selection cannot, in theory, explain all gene determined biology? Again, no, it simply means that the gene level perspective can, in practice, incline investigators to produce false explanations of biological adaptations.

Multilevel selection robustly explains the set of emotions that are motivated by our moral sense. Gene level selection’s common claim about unselfishness (and moral behavior in general) toward non-kin being kin altruism misapplied cannot directly explain two thirds of the emotions motivated by our moral sense. Based on its poor explanatory power, this common claim, which flows naturally from the gene level selection perspective, appears false. Gene level selection’s perspective appears, in practice, to have led Pinker and other gene-level-only advocates astray.

In practice, it appears that the multilevel selection perspective produces correct explanations of our moral emotions more reliably than gene level selection. Therefore, the multilevel selection perspective deserves an important place in the evolutionist’s tool kit.

Notes:
1. Unselfishness (including “altruism” and “self-sacrifice for the group”) is here defined as accepting a cost in order to intentionally benefit others without consideration of possible future benefits.
2. Tit-for-tat is a highly effective, but extremely simple, cooperation strategy in game theory (Axelrod, 1984). An agent using this strategy will first cooperate, then subsequently replicate an opponent's previous action. If the opponent previously was cooperative, the agent is cooperative. If the opponent previously tried to exploit the agent, the agent will retaliate by attempting to exploit the opponent.

References:
Axelrod, David, (1984). The Evolution of Cooperation.
Borrello, Mark E., (2005). The rise, fall and resurrection of group selection.
Darwin, Charles, (1871). The Descent of Man.
Grahama, Jesse, Haidt, J., et al. (2012). Moral Foundations Theory: The Pragmatic Validity of Moral Pluralism. Available at http://ssrn.com/abstract=2184440
Haidt, J. (2003). The moral emotions. In R. J. Davidson, K. R. Scherer, & H. H. Goldsmith (Eds.), Handbook of affective sciences. Oxford: Oxford University Press. (pp. 852-870).
Merlo, Lauren M.F., Pepper, John W., et al. (2006). Cancer as an evolutionary and ecological process.
Pinker, Steven, et al. (2012).The False Allure of Group Selection - An Edge Original Essay with Replies. http://edge.org/conversation/the-false-allure-of-group-selection


Mark Sloan’s personal interest is in showing how understanding morality as an evolutionary adaptation can be culturally useful. As associate editor of This View of Life, Morality section, his goal is to promote a cross-disciplinary view of the science of morality and how that science could be culturally useful. He has degrees in engineering and physics and has had a career in the aerospace industry.



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