Focuses on some apparently evolved features of human adolescence and their possible functions, including the pubertal growth spurt, sexual size dimorphism and bimaturism, the greater aggressiveness of males, heightened concern with one's social standing and the factors affecting it, intergenerational friction, same-sex aggregations and solidarity,…

The concept of group dialectics is considered within a temporal framework. Long-term groups are considered in terms of such temporal concepts as continuity, change, goal direction, attachment and groups in process. A conceptualization of small group dynamics based on time factors is presented. (BD)

Maintains that, although Leontiev's sociocultural orientation and its activity emphasis were inherited from Vygotsky's theory, the two men's theoretical motives and goals differed. Vygotsky's focus on symbolic mediation transforming psychological processes and Leontiev's on activities leading to internalization of action in mental processes were…

A dialectical approach is used to explore the relationship between individual specialization, collective adaptation, and rate of environmental change for both higher and lower organisms. The nature-nurture controversy and the "generation gap" are discussed in terms of this interrelationship. (BD)

Contrasts work of Leontiev and Vygotsky. Suggests that Leontiev concentrated on social activity as a whole, whereas Vygotsky made semiotic mediation through culturally developed symbols a central aspect of his analysis. Maintains that they shared a philosophical base and that Leontiev used Vygotsky's ideas as a starting point to explore human…