Why hawks win summary

Thus, Dove is not a pure ESS. If dove isnot an ESS, what about hawk? So, let's do the analysis again, this time starting with a populationmade entirely of hawks. This would be a nasty place, an asphalt junglewhere you would not want to live.

Lots of injurious fights. Although thesefights don't kill you, they tend to lower everyone's fitness. Yet, justlike with the dove population, no hawk is doing better than any other andthe resources are getting divided equally. Could a DOVE possibly invade this rough place?

It might not seem so sincethey always lose fights with hawks. Yet think about it:. Thus, if a mutant appears in the form of a dove or one wanders in fromelsewhere, it will do quite well relative to hawk and increase in frequency. Thus, Hawk is also not a pure ESS. Notice that in all of the arguments above, we made implicit assumptionsabout the relative values of the resource and the costs of injury and displaythat are consistent with the behavioral descriptions.

You probably realizethat if we changed some of these assumptions of relative value, the gamemight turn out differently -- perhaps Hawk or Dove could become an ESS. Moreover, even if we stick to the qualitative values and to our conclusionthat there is no pure ESS, the technique we have just used will not allowus to predict the frequencies of Dove and Hawk at the mixed ESS.

As wasstated earlier, the best models make quantitative predictions since theseare often most easily tested to review testing of models, press here. Thus, in the next section we will use the rules and techniques we previouslylearned to quantitatively analyze the Hawks and Doves game.

The first step of our analysis is to set-up a payoff matrix. Recall that the matrix lists the payoffsto both strategies in all possible contests:. We now need to make explicit how we arrive at each payoff. Recall thatthe general form of an equation used to calculate payoffs press here to review is:. Payoff to Strat. We will use the descriptions of the strategies given previously to write the equationsfor each payoff. But first, let's assign some benefits and costs we coulddo this later, but let's do it now so that we can calculate each payoffas soon as we write its equation :.

Injury to self -- if the injury cuts into the animal's abilityto gain the resource in the future, then the cost of an injury is assesedas a large negative. That is, injury now tends to preclude gain in the future. On the other hand, if there is one and only one chance to gain the resource,should severe injury or death be given a large negative value?

Think aboutthis, we'll revisit this situtation when we run the Hawk and Dove simulation. In the list of cost and benefits above, it is assumed thatinjury costs are large compared to the payoff for gaining the resource. Give a situation where this relative weighing might accurately reflect theforces acting on an animal. Cost of display -- displays generally have costs, although howhigh they are varies -- clearly they have variable costs in terms of energyand time and they may also increase risk of being preyed upon.

All of thesetype of measurements, in theory at least, can be translated into fitnessterms. Important Note: All of these separate payoffs are in unitsof fitness whatever they are!

You will see shortly that the values thatare assigned to each payoff is crucial to outcome of the game -- thus accurateestimates are vital in usefulness of any ESS game in understanding a behavior. Calculation of the payoff to Hawk in Hawk vs.

H contests: Relevant variables from eq. Does it seem reasonable that hawks pay no cost in winning? Instead, the Americans interpreted the Chinese reaction as an expression of fundamental hostility toward the United States. Some historians now believe that Chinese leaders may in fact have seen advancing Allied forces as a threat to their regime.

Excessive optimism is one of the most significant biases that psychologists have identified. Psychological research has shown that a large majority of people believe themselves to be smarter, more attractive, and more talented than average, and they commonly overestimate their future success.

People are also prone to an "illusion of control": They consistently exaggerate the amount of control they have over outcomes that are important to them — even when the outcomes are in fact random or determined by other forces.

It is not difficult to see that this error may have led American policymakers astray as they laid the groundwork for the ongoing war in Iraq.

Indeed, the optimistic bias and the illusion of control are particularly rampant in the run-up to conflict. Predictions that the Iraq war would be a "cakewalk," offered up by some supporters of that conflict, are just the latest in a long string of bad hawkish predictions. After all, Washington elites treated the first major battle of the Civil War as a social outing, so sure were they that federal troops would rout rebel forces.

These delusions and exaggerations cannot be explained away as a product of incomplete or incorrect information. Optimistic generals will be found, usually on both sides, before the beginning of every military conflict. The intuition that something is worth less simply because the other side has offered it is referred to in academic circles as "reactive devaluation.

What was said matters less than who said it. And so, for example, American policymakers would likely look very skeptically on any concessions made by the regime in Tehran. Some of that skepticism could be the rational product of past experience, but some of it may also result from unconscious — and not necessarily rational — devaluation.

Evidence suggests that this bias is a significant stumbling block in negotiations between adversaries. In one experiment, Israeli Jews evaluated an actual Israeli-authored peace plan less favorably when it was attributed to the Palestinians than when it was attributed to their own government. Pro-Israel Americans saw a hypothetical peace proposal as biased in favor of Palestinians when authorship was attributed to Palestinians, but as "evenhanded" when they were told it was authored by Israelis.

It is apparent that hawks often have the upper hand as decision makers wrestle with questions of war and peace. And those advantages do not disappear as soon as the first bullets have flown.

As the strategic calculus shifts to territory won or lost and casualties suffered, a new idiosyncrasy in human decision making appears: our deep-seated aversion to cutting our losses.

Imagine, for example, the choice between:. In this situation, a large majority of decision makers will prefer the gamble in Option B, even though the other choice is statistically superior. People prefer to avoid a certain loss in favor of a potential loss, even if they risk losing significantly more.

This brew of psychological factors tends to cause conflicts to endure long beyond the point where a reasonable observer would see the outcome as a near certainty. Many other factors pull in the same direction, notably the fact that for the leaders who have led their nation to the brink of defeat, the consequences of giving up will usually not be worse if the conflict is prolonged, even if they are worse for the citizens they lead. To withdraw now is to accept a sure loss, and that option is deeply unattractive.

The option of hanging on will therefore be relatively attractive, even if the chances of success are small and the cost of delaying failure is high. Hawks, of course, can cite many moments in recent history when adversaries actually were unremittingly hostile and when force produced the desired result or should have been applied much earlier.

The clear evidence of a psychological bias in favor of aggressive outcomes cannot decide the perennial debates between the hawks and the doves.

Shusha was the key to the recent war between Azerbaijan and Armenia. In fact, when we constructed a list of the biases uncovered in 40 years of psychological research, we were startled by what we found: All the biases in our list favor hawks.

These psychological impulses—only a few of which we discuss here—incline national leaders to exaggerate the evil intentions of adversaries, to misjudge how adversaries perceive them, to be overly sanguine when hostilities start, and overly reluctant to make necessary concessions in negotiations.

In short, these biases have the effect of making wars more likely to begin and more difficult to end. Hawks treat hostility at face value; doves treat docility the same way. Legal scholars like Cass Sunstein have drawn on the work of cognitive psychology to address decision making and behavior in the domestic legal and political context.