How much is temperament influenced by genetics?

Twin studies show 40-60% heritability across temperament dimensions. Genetic influence is substantial but not deterministic. Environment shapes expression and intensity of innate predispositions.

Can environment change temperament?

Environment rarely transforms core temperament but significantly influences expression. A genetically active child in stimulating surroundings becomes more engaged; in restrictive environments, frustration rises.

Do identical twins have identical temperaments?

Similar, yes; identical, rarely. They share genetics but experience different microenvironments, treatment nuances, and social interactions. Differences highlight environment's role alongside genetics.

Is temperament more fixed than personality?

Yes. Temperament shows high stability across lifespan due to genetic influence. Personality is more malleable; people change beliefs, values, and behaviors significantly through learning and effort.