There is not really much difference between the position I expressed on
this and what Nancy has now expressed. What differences exist may be
only matters of emphasis. I certainly do not reject biology (obviously,
there is nothing in human behavior which is inconsistent with biology).
Sixty years ago Susanne Langer suggested that ritual came first and that
language was derivative from 'oral' accompaniment to ritual. That
position is not too different from Tattersall's speculation, since
children's group play tends to be highly ritualistic.
Language as we know it has implicit in it not only thinking about the
world but thinking about thinking -- and it is hard to imagine that
emerging suddenly with the birth of the first homo-sapiens: hence the
assumption that the history of language is not coterminous with the
history of biologically modern humans.
P.S. One of the puzzles of animal psychology relevant to this topic is
that a number of animals engage in deceitful behavior: and deliberate
deceit implies some analogue at least to consciousness of the other's