Dollard and Miller's personality theory proposes that learning is driven by four fundamentals: drive, cue, response, and reward. There are two types of drives - primary/innate drives like hunger and secondary/learned drives like money. The development of an infant's personality is characterized by specific reflexes, innate response hierarchies, and primary drives. There are also four crucial situations in early development: feeding, cleanliness training, early sexual development, and anger-anxiety conflicts.