• Clinical classification and psychodynamics of infantile autism and early childhood schizophrenia, outlining nosology, diagnostic challenges, and developmental trajectories from infancy to school age [5], [6], [8], [9], [14].

• Growth and health determinants of early development: infant growth curves, stature/weight trajectories from birth through early childhood, and the influence of race, gender, and congenital conditions on outcomes [3], [4], [9], [11], [15], [19].

• Social-emotional development and peer relations in preschool and early school years: emergence of friendships, popularity, and emotional expression, with measures of smiling and social skills across early childhood [7], [10], [12], [16], [20].

• Cognitive development and early world representations: children's conceptions of the world, language development, and educational transitions from infancy through early adolescence [1], [7], [11], [13], [20].