Mathematicians may have found an answer to the longstanding puzzle as to why we have evolved to cooperate

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Credit: George Hodan/Public Domain

Why do we feel good about giving to charity when there is no direct benefit to ourselves, and feel bad about cheating the system? Mathematicians may have found an answer to the longstanding puzzle as to why we have evolved to cooperate.

An international team of researchers, publishing in the Proceedings of the National Academy of Sciences, has found that is favoured by in nature, offering an explanation to the mystery as to why this seemingly disadvantageous trait has evolved.

The researchers, from the Universities of Bath, Manchester and Princeton, developed a mathematical model to predict the path of evolution when altruistic "cooperators" live alongside "cheats" who use up resources but do not themselves contribute.

Humans are not the only organisms to cooperate with one another. The scientists used the example of Brewer's yeast, which can produce an enzyme called invertase that breaks down complex sugars in the environment, creating more food for all. However, those that make this enzyme use energy that could instead have been used for reproduction, meaning that a mutant "cheating" strain that waits for others to do the hard work would be able to breed faster as a result.

Darwinian evolution suggests that their ability to breed faster will allow the cheats (and their cheating offspring) to proliferate and eventually take over the whole population. This problem is common to all altruistic populations, raising the difficult question of how cooperation evolved.

Dr Tim Rogers, Royal Society University Research Fellow at the University of Bath, said: "Scientists have been puzzled by this for a long time. One dominant theory was that we act more favourably towards genetic relatives than strangers, summed up by J. S. Haldane's famous claim that he would jump into a river to save two brothers or eight cousins.

"What we are lacking is an explanation of how these behaviours could have evolved in organisms as basic as yeast. Our research proposes a simple answer - it turns out that cooperation is favoured by chance."

The key insight is that the total size of population that can be supported depends on the proportion of cooperators: more cooperation means more food for all and a larger population. If, due to chance, there is a random increase in the number of cheats then there is not enough food to go around and total population size will decrease. Conversely, a random decrease in the number of cheats will allow the population to grow to a larger size, disproportionally benefitting the cooperators. In this way, the cooperators are favoured by chance, and are more likely to win in the long term.

Dr George Constable, soon to join the University of Bath from Princeton, uses the analogy of flipping a coin, where heads wins £20 but tails loses £10:

"Although the odds winning or losing are the same, winning is more good than losing is bad. Random fluctuations in cheat numbers are exploited by the cooperators, who benefit more then they lose out."


Explore further

Researchers find selfishness can sometimes help the common good

More information: Strength in numbers: Demographic noise can reverse the direction of selection, PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1603693113
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Jul 19, 2016
This is not the whole story.

"Darwin was also aware of the ethnocentrism and xenophobia in social organisms. In animals living in groups, he wrote, "sympathy is directed solely towards members of the same community, and therefore towards known, and more or less loved members, but not to all the individuals of the same species" (Darwin, 1871, i: 163).
As regards humans, Darwin stated that "the confinement of sympathy to the same tribe" must have been the rule. This was for him one of the chief causes of the low morality of the savages. "Primeval man", he argued, "regarded actions as good or bad solely as they obviously affected the welfare of the tribe, not of the species". Among the living tribal peoples, he added, "the virtues are practised almost exclusively in relation to the men of the same tribe" and the corresponding vices "are not regarded as crimes" if practised on other tribes (Darwin, 1871, i: 182, 179).
cont>

Jul 19, 2016
Apparently Darwin had formed the opinion that natural selection acts to a great extent through intergroup competition. In his own words, "natural selection, arising from the competition of tribe with tribe,...would, under favourable conditions, have sufficed to raise man to his high position" (Darwin, 1871, i: 97).
This competition, in his opinion, could be carried out through direct conflict, even in bloody forms. "When of two adjoining tribes one becomes less numerous and less powerful than the other", he maintained, "the contest is settled by war, slaughter, cannibalism, slavery, and absorption". He was quite aware, however, that competition between groups had to be combined with cooperation within them (e.g., Melotti, 1987).
http://rint.recht...rid2.htm

-Internal altruism in conjunction with external animosity... the tribal dynamic.

Jul 19, 2016
And without the whole story it is no story at all.

Jul 19, 2016
Darwin was wrong he was a product of his sad english empire environment. Much the same systemic racism is endemic in the last failed empire today.
Darwin was a primitive racist biologist from 150 years ago not a prophet.

Jul 19, 2016
Darwin was wrong he was a product of his sad english empire environment. Much the same systemic racism is endemic in the last failed empire today.
Darwin was a primitive racist biologist from 150 years ago not a prophet.


Right on. Shows the importance of teaching science as a skill.

Jul 20, 2016
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Jul 20, 2016
The answer does not lie in mathematics. The answer lies in matters of the heart: love, compassion, and mercy. Unfortunately science can't teach us a whole lot of these important aspects of humans.


Not to mention gyre, gimble and wabe. Those three are of utmost importance to the question.

SImply because you have words doesn't mean you have something - that would be called the nominal fallacy. An example is a man having a discussion with a researcher who is studying children with autism, and the following exchange takes place:

Researcher: "we're trying to find out what causes these symptoms in these children"
Man: "Well it's obvious - they have autism"

Similiarily, love, compassion and mercy are specific forms of altruism, and what causes people to act altruistically or what altruism IS isn't explained by saying "it's love, compassion and mercy". Those are just words describing the manifestation - not explainations to it.

Jul 20, 2016
Most of the time when people talk about something they only vaguely understand, they're simply explaining words with words instead of explaining the subject.

Consider a person: "I'm tired and mentally exhausted, and my arms and legs hurt from the slightest effort. My doctors says I have fibromyalgia. It's a real condition you know."

Problem is, "fibromyalgia" is just medical latin shorthand for "muscle and connective tissue pain"; the doctor simply named the symptoms, not the disease. He doesn't know what is wrong - or does know what is wrong but also knows that you won't accept the answer if he says it's psychosomatic or psychological - and you won't go away until he agrees that you're actually ill.

Jul 20, 2016
Darwin was wrong he was a product of his sad english empire environment. Much the same systemic racism is endemic in the last failed empire today.
Darwin was a primitive racist biologist from 150 years ago not a prophet
I see. So the fact that he used words like tribe and primitive makes him a racist?

Street gangs, sports teams, political parties, and freemasons are expressions of tribalism. Explain how these things relate to racism.
love, compassion, and mercy
-And religion is a particularly virulent form of tribalism.

Jul 20, 2016
The tribal dynamic is what makes religion so dangerous.

Jul 22, 2016
I seriously doubt though, that Brewer's yeast feels altruistic from "giving to charity". Not exactly the same thing.

Jul 23, 2016
The key is not to cooperate, but to co-opt and legalize counterfeiting for only your own tribe. Then you can harvest altruism like cans of soup, while sucking the balkanized populace dry of capital

"Although the odds winning or losing are the same, winning is more good than losing is bad. Random fluctuations in cheat numbers are exploited by the cooperators, who benefit more then they lose out."

Which is why organisms tent to favor the golden ratio

Jul 24, 2016
Many things like altruism towards unrelated individuals make no sense until you consider the evolution of groups. Ask yourself if you are 100% certain groups are immune from evolutionary pressures. I suggest there is no known perfect shield from evolutionary pressures and even groups are under pressure to evolve. Our history provides plenty of examples of better organized groups out competing less well organized groups to the point of destruction of the less well organized group, a fundamental evolutionary process, I.e., survival of the fittest.

There are tremendous advantages to living in large cohesive groups. Unsurprisingly, living in such groups affects us. For example, people tend to evolve not to just to pretend to cooperate, but to actually enjoy helping each other. It becomes part of who we are to the point that we even help not just unrelated people, but even sometimes show acts of kindness to animals. This behavior is too costly to be "random."

Jul 24, 2016
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Jul 24, 2016
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Jul 24, 2016
Epoxy, I think you are correct. Frankly, with even a modest amount of historical perspective, it is obvious that our entire history is replete with competition between groups. This runs from who will eat the mammoth, to who builds the biggest ancient empire, to who wins the world war, to who reaches the moon first.

The debate over evolution has become so polarized, perhaps folks refuse to question their own view points. Evolution as a theory is correct, but that doesn't mean we understand it completely in every possible outcome. We need to get back to the roots of science, and as they say on the Science Channel, "question everything."

Pure altruism makes no sense from a competition for resources perspective, unless you involve groups. On the other hand, groups that are highly cohesive and cooperative to the point of being intrinsically altruistic can easy out-compete more divisive groups that squander resources fighting among themselves.

Jul 24, 2016
How ironic that religion, while rejecting evolution, is itself a product of evolution.

Jul 24, 2016
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Jul 24, 2016
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Jul 24, 2016
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Jul 24, 2016
Human perception (of self and of species) has co-evolved with the development of culture and technological achievements because these have been the primary tools contributing to the success of our species. Both are encouraged by cooperation. Once we figured out how to make more food than we could eat, people began finding ways to control people and have them create wealth to steal, often distorting our cooperative empathetic nature to divide and weaken us. This has continued up through the present in various forms. Soon technology will enable the whole species to communicate freely and we will free ourselves from the unnatural divisions of nationality, religion, and race. This will mark the begin of a true renaissance of human culture. Imagine all the great scientists locked by proprietary secrecy being able to collaborate.

Jul 25, 2016
This is not the whole story.

"Darwin was also aware of the ethnocentrism and xenophobia in social organisms. ..,I"the virtues are practised almost exclusively in relation to the men of the same tribe" and the corresponding vices "are not regarded as crimes" if practised on other tribes (Darwin, 1871, i: 182, 179).
cont>

The "golden rule" is part of our DNA, therefore, we can.be SOCIAL primates.

We evolved in groups, our current ability to live 'standalone', at least in parts of the world, is a total aberration over the span of history (and pre-history).

Jul 26, 2016
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