The description and classification of presidential threateners

Presidential threateners who received court-ordered psychiatric evaluations at the Medical Center for Federal Prisoners in 1981 and 1982 were studied. Using data from psychiatric reports and other background documents, the cases were analyzed according to demographic, legal, and psychiatric variables. Cases were also classified according to a system based on the characteristics of the threatener and the context in which the threat was made.     

Knowledge cannot explain the developmental growth of working memory capacity

According to some views of cognitive growth, the development of working memory capacity can account for increases in the complexity of cognition. It has been difficult to ascertain, though, that there actually is developmental growth in capacity that cannot be attributed to other developing factors. Here we assess the role of item familiarity. We document developmental increases in working memory for visual arrays of English letters versus unfamiliar characters. Although letter knowledge played a special role in development between the ages of 6 and 8 years, children with adequate letter knowledge showed practically the same developmental growth in normalized functions for letters and unfamiliar characters. The results contribute to a growing body of evidence that the developmental improvement in working memory does not wholly stem from supporting processes such as encoding, mnemonic strategies, and knowledge. A video abstract is available at: https://www.youtube.com/watch?v=LJdqErLR2Hs&feature=youtu.be     

Measurement of social dominance in squirrel monkeys

Several laboratory methods for measuring social dominance in squirrel monkeys are described.