Selfish traits not favoured by evolution, study shows

Two competing white pelicans Humans and animals could not evolve in a co-operative environment by being selfish, scientists say

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Evolution does not favour selfish people, according to new research.

This challenges a previous theory which suggested it was preferable to put yourself first.

Instead, it pays to be co-operative, shown in a model of "the prisoner's dilemma", a scenario of game theory - the study of strategic decision-making.

Published in Nature Communications, the team says their work shows that exhibiting only selfish traits would have made us become extinct.

Game theory involves devising "games" to simulate situations of conflict or co-operation. It allows researchers to unravel complex decision-making strategies and to establish why certain types of behaviour among individuals emerge.

Start Quote

It's almost like what we had in the cold war, an arms race - but these arms races occur all the time in evolutionary biology”

End Quote Dr Christoph Adami Michigan State University
Freedom or prison

A team from Michigan State University, US, used a model of the prisoner's dilemma game, where two suspects who are interrogated in separate prison cells must decide whether or not to inform on each other.

In the model, each person is offered a deal for freedom if they inform on the other, putting their opponent in jail for six months. However, this scenario will only be played out if the opponent chooses not to inform.

If both "prisoners" choose to inform (defection) they will both get three months in prison, but if they both stay silent (co-operation) they will both only get a jail term of one month.

The eminent mathematician John Nash showed that the optimum strategy was not to co-operate in the prisoner's dilemma game.

Two men hugging Co-operating is key for evolution

"For many years, people have asked that if he [Nash] is right, then why do we see co-operation in the animal kingdom, in the microbial world and in humans," said lead author Christoph Adami of Michigan State University.

Mean extinction

The answer, he explained, was that communication was not previously taken into account.

The selfish gene?

DNA molecule, artwork

In 1974, Richard Dawkins published a gene-centred view of Charles Darwin's theory of natural selection.

He argued that it was not groups or organisms that adapt and evolve, but individual genes and each living organism's body was a survival machine for its genes.

Prof Andrew Coleman from Leicester University explains that this new work suggests that co-operation helps a group evolve, but does not argue against the selfish gene theory of evolution.

Rather, he adds, it helps selfish genes survive as they reap the awards of inhabiting co-operative groups.

"The two prisoners that are interrogated are not allowed to talk to each other. If they did they would make a pact and be free within a month. But if they were not talking to each other, the temptation would be to rat the other out.

"Being mean can give you an advantage on a short timescale but certainly not in the long run - you would go extinct."

These latest findings contradict a 2012 study where it was found that selfish people could get ahead of more co-operative partners, which would create a world full of selfish beings.

This was dubbed a "mean and selfish" strategy and depended on a participant knowing their opponent's previous decision and adapting their strategy accordingly.

Crucially, in an evolutionary environment, knowing your opponent's decision would not be advantageous for long because your opponent would evolve the same recognition mechanism to also know you, Dr Adami explained.

This is exactly what his team found, that any advantage from defecting was short-lived. They used a powerful computer model to run hundreds of thousands of games, simulating a simple exchange of actions that took previous communication into account.

Man in a jail A previous study found that selfish strategies were favourable

"What we modelled in the computer were very general things, namely decisions between two different behaviours. We call them co-operation and defection. But in the animal world there are all kinds of behaviours that are binary, for example to flee or to fight," Dr Adami told BBC News.

"It's almost like what we had in the cold war, an arms race - but these arms races occur all the time in evolutionary biology."

Social insects

Prof Andrew Coleman of Leicester University, UK, said this new work "put a brake on over-zealous interpretations" of the previous strategy, which proposed that manipulative, selfish strategies would evolve.

"Darwin himself was puzzled about the co-operation you observe in nature. He was particularly struck by social insects," he explained.

"You might think that natural selection should favour individuals that are exploitative and selfish, but in fact we now know after decades of research that this is an oversimplified view of things, particularly if you take into account the selfish gene feature of evolution.

"It's not individuals that have to survive, its genes, and genes just use individual organisms - animals or humans - as vehicles to propagate themselves."

"Selfish genes" therefore benefit from having co-operative organisms.


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  • rate this

    Comment number 198.

    "Are we even subject to biological evolution any more though? Success isn't exactly correlated with reproduction in a modern society"

    Without reproduction any genetic traits don't get passed on so as far as evolution goes that's entirely irrelevent.

  • rate this

    Comment number 197.

    So the story is:
    If prisoner's can't communicate, they'll rat each out.
    If they can communicate, they'll agree the best deal for both.

    Well, who knew?

    Perhaps these guys should let the police know, it may help with their questioning techniques.

  • rate this

    Comment number 196.

    Some people seem to be devoid of empathy, as I have found out. They just don't 'get it' that it is nice to help people, without wanting something back in return. It's called being 'nice' - but to them, it's pointless as they gain nothing! I gave up trying to convert them years ago, but it's still annoying when they do it. I now keep my distance, so I don't get so mad at them.

  • rate this

    Comment number 195.

    And yet every day I see many people holding up traffic by selfishly parking on double yellow lines....

  • rate this

    Comment number 194.

    This is not new but a rehash of the brilliant work by Robert Axelrod on the Complexity of Cooperation which showed tit for tat was the best strategy, cooperating but not letting yourself be ripped off.

  • rate this

    Comment number 193.

    This is obvious and follows the arguments of evolution.

    Consider bankers again.

    Their selfish acts have left countless thousands of people in pain and poverty. Many thousands of years ago they would have been rounded up and executed - hence their selfish genes removed from the gene pool - and hence mankind becomes less selfish in time.

    Now-a-days they are protected by society.

  • rate this

    Comment number 192.

    Advancing your family/town/nation rather than just yourself is an evolutionary necessity & a sign of developed intelligence in that you understand that not only do you benefit, but so do all people you care about.

    Thinking only of yourself is a recipe for failure in evolutionary terms. History is littered with examples of such setbacks & the great societies are the ones that acted in unison.

  • rate this

    Comment number 191.

    Campbell's was the first primordial soup. From this,all other soups evolved.

  • rate this

    Comment number 190.

    Some views on what is 'selfish' are quite narrow. The opposite of co-operation is competitive behaviour. Individuals, businesses and even religious groups engage in competitive behaviour - people who make the most money or have the most children are succeeding in an evolutionary way, usually at the expense of those engaged in predominantly co-operative behaviour.

  • rate this

    Comment number 189.

    "What about those who publicly claim to be doing things for the good of everyone while in reality they're in it for themselves? The worlds of politics and business are full of such people" That pretty much defines the majority of people, even those helping others do so because it makes them feel better/happier.

  • rate this

    Comment number 188.

    How can something come out of nothing? When you look at the universe, stars, creation etc do you honestly think it happened by complete chance, just appeared and functions perfectly, do you honestly believe that?

  • rate this

    Comment number 187.

    171. chiptheduck

    If you read what the guy said - "The most adaptable to the situation/environment.

    Why have strong muscles if you need to float on water?

  • rate this

    Comment number 186.

    Yes, we see selfish, uncaring Tories evolving into even more selfish uncaring Tories (UKIP) everyday that passes. By 2015 the Tories will be indistinguishable from UKIP and the LibDems will be the New Tories.

  • rate this

    Comment number 185.

    Are we even subject to biological evolution any more though? Success isn't exactly correlated with reproduction in a modern society, in fact the opposite is often true - the most desirable members of the opposite sex will often not have reproduced at all, and nobody is that keen on a guy who's fathered 30 kids even though genetically he is doing amazingly.

  • rate this

    Comment number 184.


    It works both ways, selfish lazy unemployed, (excluding genuine unemployed or disabled) rely upon the cooperation of others to pay for & maintain their existance.

    Work is fundamentally about existinal survivablity & not about self respect or other modernistic namby pambyisms

  • rate this

    Comment number 183.

    The meek will inherit the earth - they just have to weight for evolutionary processes to deliver. A couple of hundred thousand generations might do it.

  • rate this

    Comment number 182.

    There are species like social insects that cooperate and there are species like sharks that compete and millions of others in between each with a different mix of tactics.

    As they all seem to have survived to date there is clearly no global preference.

    Adaptability to switch between cooperation or competition to suit the prevailing environment would be best.

  • rate this

    Comment number 181.

    Did evolution happen? How can something come out of nothing? I just want to challenge the fundamental evolution theory? How can planets appear and collide to form a planet that is so detailed and perfect, how was this universe created which these planets came from?

  • rate this

    Comment number 180.

    It's not new news. E.g. vampire bats are altruistic: Recently there's been publicity about bonobo apes and their moral behaviour. Ants do pretty well at working together.

    We neither own morality as a species, nor did we (or religion) initiate the concept.

  • Comment number 179.

    This comment was removed because the moderators found it broke the house rules. Explain.


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