From Alec Cawley
The scenario you describe in the experiments on altruism, that individuals have frequent “one-shot” interactions with strangers, who they never interact with again, is very unlike the real world (12 March, p 33). The fact that you have met someone once means that you have something in common, and thus may meet them again.
In particular the possibility of indirect yet significant, encounters is much stronger for a species with language and a verbal culture. Animals can only deal with a slight when they meet the offender in person, and likewise can only warn their pack in the same way. With a spoken language and tribal memory, a slight can be shared with the whole tribe and carried down the years.
Major themes of folklore include the kind deed unexpectedly rewarded, evil acts eventually punished, and long-nurtured vengeance finally achieved.
Penwood, Hampshire, UK
