head. As the song says: 'You gotta have a heart!' It may also explain why mothers rock their babies to lull them to sleep. The rocking motion is carried on at about the same speed as the heartbeat, and once again it probably 'reminds' the infants of the rhythmic sensations they became so familiar with inside the womb, as the great heart of the mother pumped and thumped away above them. Nor does it stop there. Right into adult life the phenomenon seems to stay with us. We rock with anguish. We rock back and forth on our feet when we are in a state of conflict. The next time you see a lecturer or an after-dinner speaker swaying rhythmically from side to side, check his speed for heartbeat time. His discomfort at having to face an audience leads him to perform the most comforting movements his body can offer in the somewhat limited circumstances; and so he switches on the old familiar beat of the womb. Wherever you find insecurity, you are liable to find the comforting heartbeat rhythm in one kind of disguise or another. It is no accident that most folk music and dancing has a syncopated rhythm. Here again the sounds and movements take the performers back to the safe world of the womb. From The Naked Ape by Desmond Morris. (Jonathan Cape and McGraw Hill, 1967)