Student Nature, Part II: The Natures of Our Students

Humans vary by sex, and not just in the preferred hip-to-waist ratio (Singh, 1993, 293). Firing the President of Harvard for wondering if this is true does not make facts go away (Pinker, 2006). Men are less empathetic than women (Baron-Cohen 2006; Singer et al., 266, 2006). Emotional differences between the sexes are widely recognized, even by critics of evolutionary psychology (see, for example, Buller, 2005, 317).

It is strange that genetic factors are controversial while environmental factors are widely recognized (see, for example, Elkind, 1997, 31), especially when such incontrovertible evidence like prisoners having elevated levels of testosterone (McDermott, 2006, 5)is considered. Is environmental determinism somehow less deterministic than determinism on the interaction of the environment and genetics? This has implicationss throughtout education. The existence of a disproportionately male engineering gender gap (as opposed to a disproportionately female university gender gap (Marklein, 2005) is problematic in one way if women are being unfairly excluded from opportunities (e.g., Raskin, 2005) but problematic in another way if many existing women engineers were forced into their career-paths by misguided environmental-determinists (Pinker, 2002, 359). This is not to say anything of the question if men and women learn best in different ways.


In the days where all undergrads were between 18 and 22 the interaction between DNA and age could be ignored. At most we were troubled with the issue of development (see, for example, Allen et al., 2005; Morrisey & Werner-Wilson 2005; Steinberg 2001; Steinberg & Morris, 2001). Yet once we see that certain ideas may become “hard” relatively early in life because of genetic factors (Alford, Funk, & Hibbing, 2005) the concept of teaching itself becomes troublesome. Likewise, old theories of learned development are being undermined by evidence of genetically-derived knowledge (Tooby & Cosmides, 1992), an idea once consigned to fiction (London, 1903). How will we deal with this knowledge?

Just as our experiences make students unique, so do their genes. Evolutionary simulations have shown that genetic populations instead of evolving toward agents with homogeneous behavioral strategies [that is, alleles], often evolve such that multiple strategies coexist at equilibrium” (Kurzban & Houser, 2005, 1803). This genetic polymorphism in students comes in two broad categories: genetic variation between individuals and genetic variation between groups (Rockman et al., 2005, 2214). In the future, educators will do well to be cognizant of these categories.

Some variation is merely between individuals. This is because variation between individuals is evolutionary useful for evolutionary groups (Smith et al, 2004, 5). As Sautter writes, “Evolution has cultivated a multitude of personality traits that vary amongst humans. This phenotypic variation allows for selective advantages on the group level” (2006, 4), even within just the past few thousand years (Wade, 2006). Fortunately, new technologies are helping us educate those who are smart in different ways (Yandell, 2002, 303) with different parts of their brains (Morgan, 2001) and with different “intelligences” (Gardner, 1983). But obviously we can now see only the shadows of the final consequences of the recognition genetic individuality.

But in other ways, populations vary (statistically) because of genetics, too. For instance, one pair of alleles, Dopamine Receptor D4 3 Repeat (DRD4 4R) and Dopamine Receptor D4 7 Repeat (DRD4 7R), was after some controversy found to be correlated with a type of ADHD (Castellanos et al, 1998; Grady et al, 2003) and perhaps other personality factors (Lynn, et al., 2005; Sullivan, et al., 1998).† The prevalence of “drd4 7r” varies by population, with some peoples (!Kung, Han Chinese and Sardinians) having very little of the “adhd” allele and other populations (American Indians, white Americans, Yanamamo) having elevated levels. Apparently this resulted from different evolutionary pressures (Ding, et al., 2002). Commenting on this, Harpending & Cochran (2002, 12) noted “It is probably no accident that two of the best known ethnographies of the twentieth century are titled ‘The Harmless People’ about the !Kung who have few or no 7R alleles, and ‘The Fierce People,’ about the Yanomamo with a high frequency of 7R.” As the population diversifies, population genetics will become more and more important to educators.


Student Nature, a companion series to Learning Evolved
1. The Nature of the Student
2. The Natures of Our Students
3. Nature and Her Consequences
4. Bibliography

Quick & Dirty Literature Review for the Ultimatum Game

Nothing particularly interesting. Merely a rough draft, using all new (to me) sources, of the nature of the ultimatum bargaining game. I presume that in an expanded and improved form this will re-appear, but for now I am posting it for my own reference.

Read on only if you’re very interested, or very bored.


Research has been done with gameplay and learning disabled students, such as autistics (Sally & Hill, 2006). It also also shown how attractive people both receive higher shares and are expected to give more (Solnick & Schweister, 1999), and likewise how being participants artificially divded into high and low status groups treat each other differently (Ball and Eckel, 1996), It has even be shown how research itself is a type of ultimatum game (Bonetti, 1998).

At least among some cultural groups, adolescents are more generous than adults (Hoffmann & Tee, 2006). Relatedly, moral reasoning in game play increases in early adolescence — between the ages of 11 and 13 (Takezawa, Gummerum, & Keller, 2006). Reasoning takes ability into account. For instance, players act as if higher-skill players should earn more, but lower-skill players should not be expected to give as much (Ruffle 1998).

People use different strategies while playing the ultimatum game. Researchers in Russia observed that play-types seem to split into players who want at least a fair outcome for themselves and those who want a fair outcome for both players (Bahry & Wilson, 2006). Another study observed that players seem to be split into those who are sensitive to other’s injustice to them, to injustice against others, and unjust profiting (Fetchenhauer & Huang, 2004). An unfair action is more likely to be perceived to be injust if it was intentional as opposed to unintentional (Kagel, Kim, & Moser, 1996).

Game play also varies across type of game. For instance, players who maximize for expected reward may behave fairly in ultimatum games but unfairly in dictator games (Haselhuhn & Mellers, 2005) and behave more fairly when making one decision at a time than many decisions simultaneously (Bazerman, White, & Lowenstein, 1995). Similarly, behavior in the ultimatum game changes if the actions are described in terms of an everyday social interaction rather than as straight-forward bargaining (Larrick & Blount, 1997).

Still, game performance is not static. Behavior in the ultimatum game is influenced by norms of a people (Henrich, et al., 2005) and even a workplace (Kay, Wheeler, Bagh, & Ross, 2004). Knowledge about theoretical performance maximizing behavior changes performance (Lusk & Hudson, 2004), as does group decision making (which appears to improve rational behavior) (Robert & Carnevale, 1997). Likewise, chaotic conditions make it harder to learn how to maximize performance for responders than for proposers (Gale, Binmore, & Samuelson, 1995).

Perceptions of distributive justice are important (Humprey, Ellis, Conlon, & Tinsley, 2004) as is honesty (Croson, Boles, & Murnighan, 2003). As feelings of guilty are also important (Ketelaar & Au, 2003). Thus, it is not surprising that social awareness and thus awareness of would-be fair outcomes changes behavior, too (Handgraaf, Dijk, Wilke, & Vermunt, 2003). Some of the consequcnes of this are nonintuitive: for instance, it can be better to play an economic game from a powerless position, and this appears to cause the other player to be more concerned for your welfare (van Dijk & Vermunt, 2000). Similarly, changing the relative power of the players does not substantially alter play performance (Weg & Smith, 1993).

Reciprocity in playing games means rewarding kind actions and punishing bad ones (Falk & Fischbacher, 2006). A similar concept, altruism in the ultimatum game has been observed in among the Nigerian Igos (Gowdy, Iorgulescu, & Onyweiwu, 2003). American lawyers, explaining decisions they had made, also listed fairness as a greater cause of their actions than envy or altruism-as-such (Bethwaite & Tompkinson, 1996).

The uttimatum game has also been studied through computer simulations. Adaptive algorithms can yield in-game behavior similar to that observed in humans (Calderon & Zarama, 2006). The computer programs show how fairness can evolve if players are generally able to know how the other agent has played in the past (Nowak, Page, & Sigmund, 2000).

The connection to game-play excellence with creativity is worth considering. Stubbornness and persistence are associated in computer simulations with success, but so is the less-well-regarded attitude of capriciousness (Napel, 2003). General personality traits, such as independence and tough-mindedness, are also important (Brandstatter & Konigstein, 2001);

Explicit beliefs matter, as well. An interaction between fair beliefs and self-interested explained begaining behavior in both Japan and the United States (Buchan, Croson, Johnson, & Iacobucci, 2004).
Technical measuring devises have been used to study ultimatum game behavior. For instance, the right dorsolateral prefrontal cortext (van ‘t Wout, Kahn, Sanfey, & Aleman, 2005) among other brain areas (Camerer, 2003).

The ultimatum game has been manipulated to create new games before. It has been changes to minimize the outcome of the proposing player (Gneezy, Haruvy, & Roth, 2003) as well as to incorporate elections (Sulkin & Simon, 2001) or democratic committe-style decision making (Messick, Moore, & Bazerman, 1997). Guth, Huck, and Muller altered it to prevent equal splits, and observed that proposed divisions decreased fair offers more than they expected (2001). Likewise, by reducing the size of the pie while decisions are being made, different choices are made (Suleiman, 1996). Similarly, when a rejection does not lead to all getting zero, but other predetermined positive figures, game play changes as well (Knez & Camerer, 1995). Further, when a third player is made completely dependent on the receiver player, it was found that the giving power is more generous and the receiving power less protective against exploitation (Oppewal & Tougareva, 1992).

A practical question is how the stakes of the game change behavior, and this is not nailed down yet. Increased stakes do seem to make subjects more pliant toward small rewards, but changing the stake size does not (Munier & Zaharia, 2002). Other researchers, while showing that reciprical kindness appears to explain most game behavior, note that the effective of changing the stakes is marginal when compared to the relative percentage offered (Dickenson, 2000).

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Bethwaite, J. & Tompkinson, P. (1996). The ultimatum game and non-selfish utility functions. Journal of Economic Psychology 17(2): 259-271.
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Gowdy, J., Iorgulescu, R., & Onyeiwu, S. (2003). Fairness and Retaliation in a Rural Nigerian Village. Social Journal of Economic Behavior & Organization 52(4): 469-479.
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Humphrey, S.E., Ellis, A.P.J., Conlon, D.E., & Tinsley, C.H. (2004). Understanding Customer Reactions to Brokered Ultimatums: Applying Negotiation and Justice Theory. Journal of Applied Psychology 89(3): 466-482.
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Kay, A.C., Wheeler, S.C., Bargh, J.A., & Ross, L. (2004). Material priming: The influence of mundane physical objects on situational construal and competitive behavioral choice. Organizational Behavior and Human Decision Processes 95(1): 83-96.
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Larrick, R.P. & Blount, S. (1997). The claiming effect: Why players are more generous in social dilemmas than in ultimatum games. Journal of Personality and Social Psychology 72(4): 810-825.
Lusk, J.L., & Hudson, D. (2004). Effect of Monitor-Subject Cheap Talk on Ultimatum Game Offers. Journal of Economic Behavior & Organization 54(#): 439-443.
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