Final answer:
Margaret Mahler suggested an infant's understanding of self emerges through a process of separation-individuation from caregivers, which is evidenced by the development of self-awareness as shown by tests such as recognizing oneself in a mirror around 18 months of age.
Step-by-step explanation:
Psychoanalyst Margaret Mahler has proposed that an infant's first understanding of the self is based upon the differentiation from primary caregivers, essentially learning to distinguish between the self and others. Mahler's theory is referred to as the separation-individuation process, which is part of her psychological framework that describes the phases of child development from birth to a functional individual. According to Mahler, the initial stage involves an infant being in a normal autistic phase, followed by a normal symbiotic phase, where the infant still lacks a clear inner representation of themselves separate from their mother. Through the separation-individuation process, the infant eventually develops a self-concept, gaining understanding of their individuality. This facet of psychological development is crucial, as it lays the foundation for future interactions and the developing personality. Self-awareness is a significant marker of this developmental phase, which is famously tested through the mirror test. By the age of approximately 18 months, a toddler is typically able to recognize themselves in a mirror, indicating some level of self-recognition and cognitive development.