Macer came up with the plan after asking 6,000 people in 12 countries to provide their views on moral dilemmas such as whether it is acceptable to abort a Down's syndrome baby or grow genetically engineered tomatoes. Regardless of the dilemma presented, the number of solutions proposed was never more than about 50. That result led Macer to conclude that the number of human ideas is finite, and hence could be tabulated and mapped.
The same fundamental ideasgrieving rituals for the dead, a social hierarchy, group warfare, and punishment systemsare found in all human societies and in many animal ones, too, Macer notes. "There are social customs that are unique, such as eating the hearts of your enemies in battle, but underlying them are common principles," he says. He suggests that a database of human values could clarify the diversity of behavior in different cultures and help show how genetic and social factors influence ideas. Macer invites the public's input: www.biol.tsukuba. ac.jp/~macer/mentmap.htm.


