Lenneberg's criteria for innate behaviors (1967)
  1. The behavior emerges before it is necessary
  2. The emergence of the behavior is not the result of a conscious decision.
  3. Emergence is not triggered by external events--

    4. But, the environment must be sufficiently rich for the behavior to develop adequately.

  4. Direct teaching and intensive practice have relatively little effect on development of behavior.
  5. There is a regular sequence of 'milestones' observable in the development of the behavior, and these can be correlated with age and other levels of development.
  6. There is a "critical period" for the acquisition of the behavior, after which it is very difficult to learn.

Compare, for instance,

Walking (an innate behavior)

Bicycle Riding (not innate)

General questions to ponder concerning language acquisition:

  1. How much does language acquisition depend on innate factors or knowledge?
  2. How much does language acquisition depend on environmental stimuli or experience?
  3. To what extent are Lenneberg's criteria valid for language?