An infant startling at a noise is an example of what type of reflex?

An infant startling at a noise is an example of a simple reflex, which is an automatic, non-learned response to a specific stimulus. When the loud noise occurs, the infant's nervous system responds immediately, triggering a startle response that may include jerking of the limbs or clenching of the fists. This type of reflex is innate and does not require prior experience or learning; it is hardwired into the infant's biological makeup.

Simple reflexes are among the first forms of behavior observed in infants and serve crucial functions, such as ensuring the infant's safety by reacting swiftly to potentially harmful stimuli. This demonstrates how reflexes help in survival by preparing the infant to respond quickly without the need for conscious thought.

In contrast, conditioned reflexes involve learned responses that develop through experience and association, such as Pavlov's dogs salivating at the sound of a bell. Complex reflexes would entail more intricate patterns of responses involving multiple steps and possibly higher brain functions, while instinctive reflexes are more about innate, biologically programmed behaviors typically seen in various species rather than the specific startle reaction exhibited by infants.