Studying Living Organisms

The Value of Behavioral Variation in Homo sapiens

Dawn J. Clawson
Woodrow Wilson Biology Institute

Target age or
ability group:
High school biology, introductory and advanced.
Class time
15 minutes, or more, depending on your approach.
Materials and equipment: None.
Summary of activity: The purpose of this activity is to have students look at the behavioral characteristics of their peers from a historical perspective, and realize that, in the larger scheme of a community, these behaviors do have some value, and that a society as complex as ours does need the whole variety.
Prior knowledge, concepts or vocabulary necessary to complete activity:
The principles of natural selection and the importance of variation in all traits.


In all of nature there has been natural selection of traits in a population of individuals, based upon the advantages that a particular trait confers upon an individual within a specific environment. In order for a particular variant of a trait to be selected there has to be a range of variation of that trait within the population. When we observe the behaviors of the human population there is obviously great variation. For example: introvert/extrovert, athletic/non-athletic, passive/aggressive, patient/impatient, bold/shy, to name just a very few. Does this range of human behaviors have any real advantage or value, in communal terms, either today, or in times past?


Approach A: Discuss with the students the significance, or contribution, to today's society of people with particular behavioral characteristics by considering the following questions:
What sort of occupations or careers would that type of person be likely to choose today, and what would they have chosen, or have been given, in centuries past?

An example might be an aggressive and bold person. It is possible that a person of this behavioral pattern would choose the military, law enforcement or fire fighting --in other words, an occupation that guards and protects the community. Would that person have been a warrior, gladiator or explorer in ages past?

What about an occupation for a quiet, shy person? In ages past they may have been in a retiring religious order, perhaps spending their days transcribing books for the nobility or priests. Certainly, a person of the first behavioral pattern would not have been able to do that work month after month, year after year. But what occupation would that quiet person seek today? Are they accountants, bankers, librarians, or long distance drivers?

And now to athletes. Does being athletic have any real value today? What about in times past? Would athletes have been prized for their ability to chase down wounded animals, or for being able to quickly transport important messages from one village to another?

Approach B: Another way to examine this question is to ask what behavioral patterns, or characteristics, were needed in very early isolated communities, and how are those characteristics utilized in today's complex society and then to consider what roles they may have been given during the centuries.

Approach C: This is my favorite. Tell the students a story. "Once upon a time, in the valley of ________land (your school's name) there was a very mixed society with people of all ages and manner of abilities and interests. They were interested in learning and valued an educated mind. There were noisy and quiet people, bold and shy people, the jocks and the nerds, the rough and tough people, as well as the genteel and prissy people. They were quite a mixed community, and though problems developed between individuals, these were solved without very many physical altercations.

There was, however, a roving band of rough and tough marauders, from the land of ________ (choose a name) who were not interested in anything but displays of physical strength and aggression. They had not settled into farming, were not interested in anything related to education, still hunted and gathered for their food and spent their days training for the frequent bouts of combat. Their wounded frequently died, and maimed people were not allowed to survive. Older people were seen as a drain upon their society, so they were encouraged to move out and fend for themselves, but, of course, they usually soon died after leaving their tribe.

This band of marauders came upon the land of ________ (your school). All able-bodied people were called out to defend their community, but the rough and tough and jocks were the ones who led the defense. However, they were too few in number and were not able to stop the invaders. The ________tribe killed off all but the remaining defending "warriors," for they respected the defending warriors' strength and aggression in battle. The invading band took as many supplies as they could, destroyed the community entirely, and headed off, leaving some of their females behind as mates for the warriors.

These warriors, though they were the rough and tough people, still valued the variety in their now destroyed community, and knew enough of the workings of their society to begin to re-establish their way of life as best as they could. It was a very slow process, however, for all of their technological advances had been wiped out, and they had to begin anew. As their children grew, many were just interested in the rough and tough life of physical aggression, but some began to show an interest in the things their fathers talked about... (and now you finish this story as you see fit, bringing in the variety of human behaviors and endeavors, abilities and interests.)

Comments: You may have noticed that this seems to be referring to only males and their behaviors and occupations. What were females doing in times past? Compare those things to the options that are now available to many, but not all, women. Here, the picture is not quite so clear. Is it true that women were valued for their quiet, amenable demeanor, and their ability to organize a home and household, as well as for their natural beauty? Is it possible that women who were naturally overly aggressive and assertive had a more difficult time finding a mate, and thus their genes would not have been passed on? Is it possible that the population of female Homo sapiens would have been selected for their quieter, more gentle characteristics?

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