"Run the Tape Again"

Run the tape again, and let the tiny twig of Homo sapiens expire in Africa. Other hominids may have stood on the threshold of what we know as human possibilities, but many sensible scenarios would never generate our level of mentality. Run the tape again, and this time Neanderthal perishes in Europe and Homo erectus in Asia (as they did in our world). The sole surviving human stock, Homo erectus in Africa, stumbles along for a while, even prospers, but does not speciate and therefore remains ...

 Experimental Methods for Understanding Babies

But why should you believe us instead of those benighted experts who thought babies couldn't really see? How can we say we actually do know what babies think? With the help of videotape, scientists have developed ingenious experimental techniques to ask babies what they know. One whole set of techniques has been designed to answer two simple questions: Do babies think that two things are the same or different? And if they think they're different, do they prefer one to the other? You can prese...