Educational psychology : an objective study / by Peter Sandiford.

  • Sandiford, Peter, 1882-1941.
Date:
1928
Catalogue details

Licence: In copyright

Credit: Educational psychology : an objective study / by Peter Sandiford. Source: Wellcome Collection.

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    was shown that the potentialities of behaviour resided in the genes of the chromosomes. Not all the genes or combinations of them are developed by environment. Each individual represents but a portion, probably a very small portion, of his hereditary possibilities. The selective agency is environment. This deter¬ mines the particular combinations of genes which shall be realized in actuality. Thus the genes of man determine, for example, that under the stimuli of food and use he grows arms instead of wings, while the genes of a chicken under similar stimulation lead to wings instead of arms. And the behaviour possibilities of arms and wings are totally different. The same stimuli of food and use also determine whether a particular man shall grow big, hard muscles or small, flabby ones. But it is the genes that fix the limits of muscular development for each particular individual. Further, the genes do not start their own development; the starting agency is environment. An organism is no self-starting mechanism ; its reactions are always started by some stimulus outside of itself. Since, as we have seen, each cell of a multicellular organism contains identical chromosomes, there must be some agency determining which cells shall develop into muscle cells, bone cells, and the like. The agency determining this development, and consequently the behaviour patterns of the individual, is, according to Child, the physiological gradient.1 (3) The kind of behaviour an organism exhibits is dependent upon its structure and constitution, and upon the nature of the exciting stimulus. Differing organisms will behave differently even when excited by the same stimulus. If one could imagine a situation in which a partridge, sparrow, deer, and man were startled simultaneously by the same noise, the resultant behaviour would be very different. The partridge would freeze, the sparrow fly, the deer run, and the man start. (4) The grade or level of behaviour is dependent upon the grade or level of biological development of the organism. Behaviour runs from low to high, high being defined as the greater capacity for diversified living. The greater the biological development of the organism, the higher is its behaviour. Plants undoubtedly behave. If Bose’s researches are confirmed, they may even have a primitive kind of nervous system. Plants, however, are fixed in location ; they may react towards light, heat, winds, and moisture, but such adjustments as they make are necessarily to a narrower environment than the adjustments that animals make. Again, animals of simpler biological structure, x Child, Physiological Foundations of Behaviour, chaps, vi, vii, and viii.