From Howard Shevrin:

Re: Built-in brain “templates” may clue tots to threats (Sept. 18): Fascinating. Five months seems pretty old. Studies using time of attention have been done with much younger infants. That should be their next step. Funny they don’t cite the Spitz research identifying a smiling template at a very young age. The survival value of a baby’s smile is obvious. It appears very early, about 2 weeks I think.

So you won’t misunderstand about my not signing the letter: 1) I do think the att/rel is mainly your baby, 2) as you know I still have misgivings about the fundamental basis for the distinction that as yet I cannot fully and persuasively justify, but it’s there and I devote much thought to it and the whole issue of similarity.