So whattaya get for being nice?

kw: book reviews, nonfiction, evolutionary theory, altruism

"...for scarcely for a righteous man will anyone die, though perhaps for a good man someone would even dare to die." (Romans 5:7)

Would you die for another? Have you ever taken a risk for another's sake? Why would anyone in a right mind do so?

Altruism is defined a number of ways. To some, it means taking a risk, even risking death, for no apparent return or recompense. To others, it means working to benefit others at some cost to oneself, though in a social setting where "what goes around comes around." To others it is being good when you don't have to.

I've worked as a lifeguard. There is nothing like saving a life...what a rush! But, wait a minute!! Where does that rush come from? It's a chemical reaction in my brain, which means there are genes that produce proteins that give me this towering feeling when I do something heroic. Why would such genes ever evolve? What's in it for them?

What, indeed? It doesn't take much looking to find that most animals—at least the warm-blooded ones we can sort of understand—engage in caring behaviors, not only with family members and other kin, but with unrelated acquaintances. Caring for kin one can understand; it helps more of those carrying at least some genes that match yours have successful offspring. And, the social environment tends to help all members toward reproductive success.

But in social insects, we find the majority of members of species such as bees and ants perform all the grunt work for their colonies, with no hope of reproducing. How could such species evolve in the first place?

Darwin puzzled over this, and proposed only partial answers. Many, many others have done so since, and today we actually have a mathematical theory, part of which is expressed as "I'd die for two brothers or eight cousins." This reflects the fact that your siblings each contain half the same genes you have, and that a cousin shares one-eighth of them.

The 150-year saga of the theory of genetic altruism is ably presented in The Altruism Equation: Seven Scientists Search for the Origins of Goodness by Lee Alan Dugatkin, a Biology professor in Louisville.

The author focused his investigation on the four primary British evolutionary scientists—Charles Darwin, Thomas Huxley, J.B.S. Haldane, and W.D. Hamilton—, two Americans—Warder Allee and George Price—, and the Russian prince Petr Kropotkin.

Darwin made a strong case for altruism, and behavioral tendencies in general, being just as subject to natural selection as any other traits, though he frankly didn't know quite how to prove the point. Little did he know how long it would take.

Huxley and Kropotkin were exact opposites in viewpoint, largely because of their own formative experiences. Huxley, raised in crowded poverty, in a violent milieu, promoted "Nature red in tooth and claw", using the metaphor of gladitorial combat for the struggle for resources. Kropotkin, raised with more privilege, but experiencing Siberian living for many years, saw cooperation on every side, and promoted "mutual aid" as the way members of most species gained a greater share of resources; for him, the struggle was against the environment, not against one's fellows.

Haldane, Allee, and Price each added their piece to a mathematics of the tendency to help others, but it was left to Hamilton to develop the theory in full form. Now it is a commonplace that any of us shares almost exactly half of the genes of each parent, the same proportion with each sibling. Half-siblings share only a quarter, and so on...at least in "outbred" populations. I'll consider inbreeding in a moment.

The basic equation is very simple: if c is the cost of an action, b is the benefit that accrues from it, and r the relatedness one has with the object of the (beneficial) action, then whenever br>c, the action is more likely to be performed. If there is a gene (or a gene complex) for altruism, this equation shows how it takes care of its own survival.

For example, it may be that swimming in icy water to save a sibling entails a risk of 1/10 that you will instead lose your life. The cost is 0.1. The benefit for a successful rescue is 1.0 to the rescued sibling. The relatedness is 0.5, because half of your genes will be preserved because of the life you save. Thus br=0.5, which is greater than 0.1. Should the risk (icier water, a longer swim, fast current) cause the cost to approach 0.5, you are more likely to have second thoughts.

The math required to actually determine r can be quite complex, particularly in inbred populations. For example, I have an ancestor who was born on Nantucket Island, then left for North Carolina in the 1700s. He was of the sixth generation from the founders. Nantucket was founded as a Quaker colony by ten families in the 1620s. A generation later, a few more families came, and their parents (in the Old Country) were of the same generation as the ten founding families.

This ancestor of mine, named Joe, had 2 parents, 4 grandparents, and so on, back to 32 ancestors of the founding generation. Of course, ten couples only provides twenty ancestors. As it turned out, he was descended from only seven of the founding families, or fourteen in that generation. He was also descended, in the fifth generation back, from three couples of the later comers, or six couples from the Old Country in the founding generation, for a total of 14+12 = 26 unique ancestors. Thus among his ancestors were a few sets of cousins who married.

As it happens, his parents were third cousins, his father's parents were second cousins, and one of his mother's ancestor-couples were first cousins. I haven't gone through the math, mainly because I haven't looked at Hamilton's work in detail to figure out how he would do it. But, I'd guess that, if 32 unique, unrelated ancestors produces a relatedness among two siblings of 0.5, then 26 ought to boost that to about 0.6. Thus, inbred populations will have larger r factors, and should exhibit increased altruism.

This is exactly what we see, in humans and animals both. At its most extreme among mammals, a naked mole rat is found to share 0.8 or more genes with any random colony mate, which is greater than the 0.75 found among the sterile workers in social insect species. So it is no surprise that these mammals have a social life more reminiscent of ants than of other mammals.

Well, all of these are fun facts. There is another side, thought, that the book scarcely mentions. Altruism toward strangers cannot be of the same source as kin-based altruism. Herewith, my own thoughts:

In old Western movies, we see everyone is really polite, because everyone is armed, and frequently, quick to take offense. Lack of niceness is likely to be answered with hot lead. Today, the situation is the same in many inner cities, but even in the suburbs, the chance that a random person who takes offense might take a poke at you is a pretty good reason to be at least polite, and better, helpful if requested.

Secondly, what goes around comes around. Those who are known for helpfulness are more often helped by others, even those less disposed to be helpful.

And thirdly, there must be some gene complex that produces variable amounts of altruistic-toward-strangers behavior, to account for the rush I felt whenever I saved someone's life or health. Some people have more—and thus are more likely to work in a "helping profession" like medicine, nursing, or the ministry. Others have less, and among these we find variously unpleasant people, the jerks we dread, for example, or the perennial moochers, and of course career criminals and psychopaths.

Just as the offspring of two tall parents are likely to be tall, but vary a lot in height anyway, the offspring of two "good" (or two "bad") parents may be similarly disposed, but will vary from one to another. A case in point, my own family:

First, height: Father 6 feet, mother, 5'6" (tallish). Four sons: 6 feet, 6'2", 5'8", 5'9" (not in birth order).

Second, "goodness": Both parents from ardently Christian families, raised to be helpful folks, and they really are. Four sons: all tend to be helpful, but they vary quite a lot (I will go no further...).

I suspect there is thus another factor in Hamilton's equation, call it t, for the tendency to be helpful. It ranges from zero to infinity. Then if tbr>c, an altruistic action is likely to be carried out, otherwise, unlikely. Where t is around 1.0, the "hamiltonian" situation ensues. Real jerks have t less than 0.5, while others have t of 2 or 3 or greater, so that "everyone is like a brother." Considering that r is never really zero (we're all descended from Noah, way back when!...or from a small pool of early humans), we all have at least a little tendency to help just about everyone.

And that's a good thing.