EXPECTATION (Lat. expretatio, from cx pcetarc, to expect, from ex, out + spectorc, to behold, from spicerc. to look). Like belief (q.v.), this term must be treated by psychology under two headings: as a complex mental process, characteristic of certain consciousnesses, and as a state of consciousness itself. (See ATTENTION.) (1) There is general agreement upon the point that expectation, regarded as an item of con crete experience, must be classed among the emotions. The analysis offered by the different psychologies differs, however, according as the author recognizes two or more than two quali ties of affection (q.v.). If We believe that pleasantness and unpleasantness are the sole af fective qualities, we may say that expectation is a eollective term, including both hope (pleasant. expectation) fear (unpleasant expectation) ; just as surprise is a collective term. ineluding the emotions of pleased and of unpleasant sur prise. (See Extormx.) Or we may do as, e.g. Kiilpe does—assume the existence of two types of emotion: one characterized by the predomi nance of an affective quality, the other by that of a peculiar complex of organic sonsat ions. This supposition tiePTIN, however, rather to cut than to meet the difficulty. If, on the other hand, we posit a large of affective qualities, we can base expectai ion upon the quality of tension, as joy upon that of pleasantness. :Teelings of tension and relaxation," says Wundt, "are al ways connected with the temporal course of processes. Thus, in expecting a sense impression, we note a feeling of tension, and, on the arrival of the expected event, a feeling of relaxation. Both the expectation and the satisfaction may be accompanied, at the same time, by a feeling of excitement, or, under special conditions, by pleas urable or unpleasurable feelings. These other feelings may, however, be entirely absent." Wundt thus admits the possibility of an indiffer ent (neither hopeful nor anxious) expectation, which shall he simply tense or strained. In the present unsettled condition of affective psychol ogy, it is unwise to make a choice between these two conflicting views; judgment must be reserved until such time as the emotive processes have been brought under experimental control.
(2) Considered as a state of consciousness, ex pectation may be defined as an anticipatory or preparatory attention. In expecting an impres sion, we set ourselves for its reception; partly by the proper adjustment of the sense-organ to which the impression will appeal; partly by imaging the occurrence, forming an idea of it;_ partly by taking up an appropriate bodily atti tude, and so securing the most favorable back ground of organic sensations; partly, it may be, by rehearsing, mentally, the judgment that we shall pass upon the event when it takes place. It is clear, from this analysis, that a suitable direction of expectation is the sine qua non of a full apprehension or clear apperception of the impression. Hence it is customary, in all forms of psychological experimentation, to give a signal (a spoken 'Nov!' or the stroke of an electric bell) to the observer, at such an interval before the presentation of stimulus that expecta tion may just have time to reach its maximum, without passing over into fatigue. The time
required, at least in the simpler departments of experimental work, amounts to 1.5 or 2 second,. During this period, the observer has an oppor tunity to concentrate himself upon the problem in hand, either in a general way, by banishing irrelevant ideas and thoughts, or, more specifical ly, by calling up a definite mental image of the coming stimulus. Suppose, e.g. that the two points of a pair of compasses arc to be set down simultaneously upon the skin of the wrist, at a certain distance apart, and that the observer is to say whether he senses one or two pressures. On hearing the ready-signal, he will (a) devote his attention exelusively to the wrist, and pur posely ignore any accidental stimulation of eye or ear; while (b) if he has had previous experi ence in the dise•iminatiott of two points upon the skin, he will represent to himself, in terms of pressure sensation, the various forms that cuta neous `twoness' may take.
Expectation. then, if rightly directed, is of essential service to the experimental psychologist. But the predisposition of consciousness may he a source of error, as well as a help, in laboratory work. Suppose that we wish to ascertain the least separation of the compass points that can evoke the introspective response 'two pressures.' We shall begin with a separation of the points at only one pressure is sensed, and gradual ly increase this separation, in successive trials, until the judgment 'one' passes over into the judgment Iwo.' We secure the observer's full attention, at each application of the instrument, by means of our ready-signal. Since, however, we are making a series of tests, and the series is progressing in a known direction (from one ness toward twoness), the observer can hardly remain unprejudiced; at each fresh step of the series he will think, "This time there must he two!" The judgment 'two' will, themfore, come too soon; our result is vitiated by the error of expectation. In all such cases some method must be devised whereby this error may be eliminated. In the present instance we eliminate it, very simply, by reversing our series. We begin a second set of tests with a separation of the compass points that gives two clear pressures, and work down, step by step, until 'two' passes over into 'one.' The 'one' comes as much too soon, in this reversed series, as the 'two' came too soon in the preceding series. By averaging the results of the two series, we rule out the ex pectation error.
Consult: Wundt, Outlines of Psychology (Eng. trans., Leipzig, 1898) ; Killpe, Outlines of l'sychology (Eng. trans., London, 1895) ; Titche ner, Primer of Psychology (New York, 1900) ; id., Experimental Psychology (New York, 1901). See FATIGUE; HABIT; PRACTICE; PSYCHOPHYSICS.