trait

Trait refers to a characteristic that can be observed or measured in an organism, population, or individual. In biology, traits include morphological features such as leaf shape or coloration, physiological properties such as enzyme activity, and behaviors. Some traits are genetic, determined by DNA sequence, while others arise from environmental influences. The distinction between genotype (the genetic makeup) and phenotype (the observable trait) is central in genetics. Many traits are polygenic, shaped by multiple genes and their interactions with environmental factors, while others follow Mendelian patterns with simple dominant and recessive alleles. Trait variation within populations provides the material on which natural selection acts and can lead to evolutionary change.

In psychology, a trait is an enduring pattern of thinking, feeling, or behaving that differentiates individuals. Trait theories of personality describe consistent aspects such as extraversion or conscientiousness. These traits are typically measured with standardized assessments and are considered relatively stable over time, though they can be influenced by context and development. The term trait also appears in other domains, referring to a characteristic of an entity, such as a data object in computing or a feature used to describe a species or population. Overall, traits are used to categorize and compare differences among organisms, individuals, and systems.