Psychology.—We turn to the psychological aspect of instinct. Here, although even less is definitely known than on the ;biological side, three problems stand out in bold relief. We have to investigate the mental processes that are present in the instinctive act (the action consciousness), to describe other mental states which are conditioned upon instinctive tend encies, and to work out the relation of in stinct to meaningful experience. As regards the first, work on the human organism seems to show that the instinctive is of the same type as the sensori-motor act, i.e., the perception of the object touches off the reaction, there is necessarily no conscious representation of the determination to act or of the action's end. We have no reason to suppose, therefore, that, for instance, the wren is in the least aware of what it is doing or why it is doing it when it builds its nest. This does not mean, however, that, accompanying the instinctive act, there is no psychological experience. On the contrary we may safely assume that even in the lowest forms of animal life some sort of sensory experience releases the disposition and to an extent determines the subsequent course of the action. Secondly, psychologists are agreed that, particularly in the case of the grosser emotions, the emotive is an instinctive con sciousness, and the psychology of the emotions is, therefore, in a sense a psychology of in stincts. In fear, for example, the vasocon striction, the rapid heart-beat, the spasmodic respiration, the glandular secretions are toadied off by instinctive tendencies, and the correlated patterns of organic sensations and feelings form the core of the mental experience. Aside
from this general statement little is established as regards either a detailed description of the emotions or of their number and variety. It is, perhaps, because of their instinctive basis that psychology has found it difficult to bring the emotive instincts under experimental con trol. Finally, the more we learn about in stinctive tendencies the more apparent it be comes that the situations from which they proceed are meaningful, but we need not sup pose that the organism is necessarily aware of the meaning. The chick in the egg feels (we may only guess as to its nature) a vague dis comfort, and the complicated reaction by which it makes its egress from the shell is released. How this particular tendency to react thus to this particular situation originated is a question which cannot be answered until biology has given us a satisfactory theory of the origin and transmission of instincts—a task that must await a more detailed description of the nervous correlations involved. Consult Baldwin, J. M., 'Mental Development> (New York 1906) ; Hobhouse, L. J., 'Mind in Evolution> (London 1901) ; Jennings, H. S. 'The Behavior of Lower Organisms> (Washington 1904) ; James, W., Principles of Psychology> (New York 1890) ; McDougall, W., 'Social Psychology' (London 1908) ; Morgan, C. L., 'Instinct and Experience' (New York.1912); Titchener, E. B., 'Beginner's Psychology' •(New York 1915) ; Watson, J. B., 'Behavior' (New York 1914) ; Wundt, W., 'Lectures on Human and Animal Psychology> (New York 1901).