An infant's emotional reactivity and intensity is referred to as its

Attitude typically refers to an individual's learned predispositions toward certain ideas, objects, or people, often developed through experience and socialization. Unlike temperament, which is inherent and biologically driven, attitude is shaped over time and does not reflect an infant's natural emotional responses.

Emotionality describes the capacity to experience emotions and express them, but it is a broader term that does not specifically refer to the intrinsic emotional reactivity of infants. While emotionality can encompass aspects of temperament, it lacks the specificity and focus on innate characteristics that temperament provides.

Heritability refers to the proportion of variation in a trait that can be attributed to genetic differences within a population. While temperament can be influenced by genetic factors, heritability itself is not a descriptor of an infant's emotional characteristics but rather a measure of the genetic contribution to various traits.

Personality encompasses the enduring patterns of thoughts, feelings, and behaviors that are characteristic of an individual. While personality develops from temperament over time, it is not an accurate term for describing the emotional reactivity and intensity seen in infants, which are more aligned with the concept of temperament.