Age (m.)


Behavioral features


1. reflex


Stereotyped responses to sensory stimuli


Roots and sucks

2. primary circular reaction


Action centered on infants' own body ("primary") where they learn how to reproduce an action, reinstate an event

a-Repetitive coordinations

b-First acquired adaptations

c-Recognition of various objects and contexts

Repeats hand-clapping

Shows conditioned reflexes

3. secondary circular reaction


Repeated ("circular) attempts to reproduce environmental ("secondary") events intially discovered by chance.


Semi-intentional actions (initial act by chance) but later ones are. Active attempts to effect changes in environment

Swings object and watches and listens to result, repeats it over and over…

4.coordination of secondary behaviors


Two or more independent behavioral acts become intercoordinated, one serving as instrument to another.


b-goal directed

c-establishes relation between two objects

d-coordination of several behaviors toward object or person

Sets aside an obstacle in order to obtain an object behind it.

5.Tertiary circular reactions: Experiment-ation


Child is curious about possible functions of objects and explores potential of an object through trial and error experimentation

Behavior less stereotyped as child invents new patterns.

Repetitive trial and error begins.

Interest in novelty.

Considers others as autonomous


Experimentally discovers that one object, such as a stick, can be used to obtain another object.

6. Invention of new means through mental combinations:


18+ months

beginnings of human language fluency- 2 to 4 word strings.


Solutions obtained mentally, not by overt trial and error.

(But T&E can be done in the head, forseeing the consequences of actions--hence the term "insight."


Child can represent objects and events not present


Mentally figures out how one object can be used to obtain another object.

Table 2 Characteristics of sensorimotor intelligence

(See Gomez, around Fig 3.1 for more discussion. It is my (JL) impression that apes can reach the beginnings of the figurative-symbolic stage in Piaget's stages-- the level of two year old humans.)

Wolfgang Kohler (1876-1969) used the term "insight" as a visual metaphor for manipulating images:

"the insight of the chimpanzee shows itself to be principally determined by his optical comprehension of the situation..p. 277 many cases in which the chimpanzee stops acting with insight, it may have been simply that the lie of the land was too much for his visual grasp (relative "weakness of shape perception").

Experiences with sticks and relevant objects may be a prerequisite for "insight" regarding those objects.

Kohler, W. (1925). The mentality of apes. New York: Harcourt, Brace and Co.