Approach and following behaviour of 24-hr old chicks as a function of stimulus complexity

In a straight runway, following or approach behaviour of day-old broiler and leghorn chicks was found to be mainly a linearly decreasing function of stimulus complexity. The patterned stimuli used were checkerboard-like matrices containing, on the average, 4, 36, 100, 400, or 900 bits of information. Preference for simpler stimuli was not found to depend upon experience in the test situation nor upon the degree of complexity of the home pen. When stimulus illuminance was varied, there was a tendency for a plain grey square (zero bits) to be preferred over the pattern containing 4 bits of information, suggesting that approach or following behaviour is energized maximally by some optimal combination of stimulus illuminance and complexity.