In recent years there has been much research interest in looking for behavioural phenotypes (or specific profiles of strengths and weaknesses) that are associated with specific conditions--particularly conditions with genetic origins such as Down syndrome. This kind of information may be very helpful in alerting parents and professionals to the…

Although the verbal operants that comprise Skinner's account of verbal behavior provide a seemingly complete description of the behavior of the speaker with respect to what is ordinarily called the expression of meanings, it may be shown that the account is intrinsically deficient in describing the receptive behavior of listeners with regard to…