These words refer to traits that are deeply ingrained as part of a functioning pattern. Scientifically, innate refers to qualities, traits, etc., existing from birth, and thus has the opposite sense to acquired characteristics. But it also has a general use for something deep-seated in the character or personality and, of all these words, is the least specific in suggesting how or at what point a trait becomes of such intrinsic importance: an innate weakness of all electric powered cars; an innate eagerness to learn that was challenging and exciting; questioning whether learned responses ever do become innate . Inborn and inbred are the most informal words in this group; in effect, they split innate into two separate halves. Inborn indicates those traits acquired before birth, inbred those traits acquired later through training: inborn musical ability; an inbred respect for other people’s wishes. The split is not so neat as it appears, however, since inborn is not always clear about environmental influences during gestation and inbred is not clear about the distinction between the contingent effects of environment during infancy and later training.

Congenital presents a conflicting set of meanings that render it vague and open to misinterpretation. In its most specific sense, it refers to traits acquired during gestation and not through heredity or later training; the tragic proof that thalidomide causes congenital deformities. In a completely contrary meaning the word refers to traits acquired any time from birth onwards: a congenital liar. In this instance, it would seem clearer to use habitual or some other word. In still another instance the word can refer in vague and general way to traits deeply imprinted, without specifying when the imprinting occurred; this would make it a more formal synonym for innate . The word is sometimes used in this context with humorous intent: the farmer’s congenital distrust of "city slickers."

In its biological sense, hereditary is distinguished from congenital in its reference to characteristics, as the colour of the hair and eyes, which are transmitted or transmissible directly from an animal or plant to its offspring. In an equally specific legal sense, hereditary applies to that which passes, is capable of passing, or which of necessity must pass by inheritance from an ancestor to a heir: a hereditary estate. In a more general way the word is used to refer to anything a person possess which had to do with or was in some way a characteristic of one or more of his ancestors: the difficulty of dealing with a hereditary enemy towards whom one feels no personal animosity.