1. a theory that avoidance behavior is the result of two kinds of conditioning. Initially, stimuli that precede the presentation of the stimulus to be avoided (e.g., an electric shock) are established as aversive by classical conditioning (Factor 1). Next, the subject learns to terminate the conditional aversive stimulus by means of escape conditioning (Factor 2). [proposed by O. Hobart Mowrer]

2. a theory that intelligence comprises two kinds of factors: a general factor, whose influence pervades all tests of intelligence, and various specific factors, each of whose influence extends only to a single test in a test battery. [proposed in 1904 by Charles Spearman]