Final answer:
The third essential feature of an instinct is that it is observed in 'Common' members of a species, as innate behaviors are genetically wired and do not require learning.
Step-by-step explanation:
The universality of instincts among common members of a species constitutes a fundamental feature, highlighting their innate and genetically predisposed nature. Unlike learned behaviors that vary based on environmental factors and individual experiences, instincts are hardwired into the genetic code of individuals within a species. This inherent quality ensures that instincts manifest uniformly across common members of a given species.
In human beings, simple reflexes, such as the involuntary contraction of muscles when exposed to a sudden loud noise (startle reflex), exemplify instinctual behaviors. These reflexes are observed universally in humans, regardless of cultural or environmental differences. Similarly, the animal kingdom presents numerous examples of instinctual behaviors exhibited by common members of species.
In insect colonies, the intricate social interactions and division of labor among members showcase instincts that contribute to the overall survival and functionality of the colony. Worker bees, for instance, instinctively know their roles in tasks like foraging, nursing, or building the hive without prior learning or guidance.
The widespread occurrence of instincts in common members of a species emphasizes their essential role in survival and adaptation. These innate behaviors provide a foundational framework for individuals to respond appropriately to specific stimuli or situations, contributing to the overall fitness and success of the species. While instincts can coexist with learned behaviors, their common manifestation among members of a species underscores their genetic basis and evolutionary significance.