It is nice to think that there are so many unsolved puzzles ahead for biology, although I wonder whether we will ever find enough graduate students. - Lewis Thomas

It is my belief, based partly on personal experience but partly also arrived at by looking around at others, that childhood lasts considerably longer in the males of our species than in the females.

Perhaps the safest thing to do at the outset, if technology permits, is to send music. This language may be the best we have for explaining what we are like to others in space, with least ambiguity. I would vote for Bach, all of Bach, streamed out into space, over and over again. We would be bragging of course, but it is surely excusable to put the best possible face on at the beginning of such an acquaintance. We can tell the harder truths later.

Maybe altruism is our most primitive attribute out of reach, beyond our control. Or perhaps it is immediately at hand, waiting to be released, disguised now, in our kind of civilization as affection or friendship or attachment. I can’t see why it should be unreasonable for all human beings to have strands of DNA coiled up in chromosomes, coding out instincts for usefulness and helpfulness. Usefulness may turn out to be the hardest test of fitness for survival, more important than aggression, more effective, in the long run, than grabbiness.