"Development results in new characteristics and new abilities." This statement…

Developmental psychologists distinguish ‘growth’ — a quantitative increase in size or physical dimensions — from ‘development’, which is the qualitative, progressive series of changes (through maturation and learning) that produce new characteristics, structures, and abilities in an individual across the lifespan.

The statement quoted in the question — that development results in new characteristics and new abilities — is the definition of development given by Elizabeth B. Hurlock, who described development as an orderly, cumulative sequence of changes leading to the emergence of new capacities and traits, distinguishing it from mere physical growth.

• Gesell — associated with the maturational theory of development (a fixed, genetically timed unfolding of behavioural and motor patterns), not this definitional statement.

• Meredith — associated with longitudinal growth studies (height and weight norms across childhood), a growth-measurement contribution rather than this definition.

• Douglas and Holland — not the source credited with this specific definitional statement in developmental-psychology teaching material.

Hence, the statement is Hurlock's definition of development, making Hurlock the correct answer.