One common criticism is indeed that personality type models can give the impression that our personalities are set in stone. However, in reality, we're dynamic beings. We grow, we change, we evolve. This is one area where the interplay between personality types and personality traits comes into focus.
Personality traits, as described by the Five Factor Model (Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism), are considered to be relatively stable over time, but they are not completely unchangeable (McCrae & Costa, 1987). These traits provide a baseline, but how they're expressed can vary depending on the situation.
Now, personality type models, like the Myers-Briggs Type Indicator (MBTI), suggest a more static view, placing individuals into one of 16 types. But even here, it's not about being "locked" into a particular type. The intention is to provide insight into one's natural preferences or tendencies, not to suggest determinism (Myers et al., 1998).
Think of it like being right or left-handed. Just because you prefer using your right hand doesn't mean you can't use your left. It's just a preference, not a restriction. Similarly, a person with a preference for introversion on the MBTI can still enjoy and engage in social activities - it's just that they might also need time alone to recharge.
As we navigate through life, we learn, we adapt, and we sometimes even change aspects of our personalities. An introverted individual might develop more extroverted behaviours due to their job requirement, for example. These experiences don't change our core selves, but they do shape how we express our personalities.
In the end, any model is a simplification of reality, and personality type models are no exception. They're useful tools for understanding broad patterns in human behaviour, but they don't capture the full complexity and dynamism of human personality.
References:
McCrae, R. R., & Costa, P. T. (1987). Validation of the five-factor model of personality across instruments and observers. Journal of personality and social psychology, 52(1), 81.
Myers, I. B., McCaulley, M. H., Quenk, N. L., & Hammer, A. L. (1998). MBTI Manual (A guide to the development and use of the Myers Briggs type indicator). Consulting Psychologists Press.