Facing the situation: Testing a biosocial contingency model of leadership in intergroup relations using masculine and feminine faces

Using an evolutionary psychology framework we propose that leadership and followership are evolved traits to solve recurrent group coordination problems. We argue that adaptive problems such as those concerning intergroup conflict or cooperation activate different cognitive leadership prototypes, and the face conveys diagnostic information about the suitability and emergence of intergroup leadership. Consistent with hypotheses we find that followers expect masculine-faced leaders to behave competitively and feminine-faced leaders cooperatively in intergroup relations. Furthermore, individuals prefer leaders whose facial cues match the adaptive problem. For example, a masculine-looking leader is preferred in a competitive intergroup setting. Also, this match between face and situation is reinforced with a consistent leadership message such as a masculine-looking leader expressing the need for competition. An evolutionary perspective provides a deeper understanding of the biological aspects of leadership and generates many novel hypotheses about how markers such as the human face affect leadership emergence and effectiveness.     

Robust estimation of the exponential mean parameter for small samples: Complete and censored data

This paper studies methods for simple estimation of the exponential mean parameter in small samples in the presence of outliers. Existing estimation methods are discussed. Adaptation of these methods to allow for Type I censoring is investigated. New robust procedures are proposed. A series of simulation experiments Indicate trimming provides significant protection against outliers while the premium is usually small when trimming uncontarninated samples. A linearly weighted mean is recommended for uncontarninated samples, both censored and complete. In larger samples, (n - 20), the proposed Huber-type estimator performs quite well in all situations of censoring and contarnination