criminal psychology-第124节
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t in the woods； go round in a significantly small circle。 It is frequently observed that persons； who for one reason or another； i。 e。； robbery； maltreatment； a burglarious assault； etc。； had fled into the woods to escape； found themselves at daybreak； in spite of their flight； very near the place of the crime； so that their honesty in fleeing seems hardly believable。 Nevertheless it may be perfectly trustworthy； even though in the daytime the fugitive might be altogether at home in the woods。 He has simply underestimated the deviations he has made； and hence believes that he has moved at most in a very flat arc。 Supposing himself to be going forward and leaving the wood； he has really been making a sharp arc； and always in the same direction； so that his path has really been circular。
＇1＇ Cf。 Entwurf； etc。
Some corroboration for this illusion is supplied by the fact that the left eye sees objects on the left too small； while the right eye underestimates the right side of objects。 This underestimation varies from 0。3 to 0。7％。 These are magnitudes which may naturally be of importance； and which in the dark most affect deviations that are closely regarded on the inner side of the eyei。 e。； deviations to the left of the left eye or the right of the right eye。
Such confusions become most troublesome when other estimations are added to them。 So long as the informant knows that he has only been estimating； the danger is not too great。 But as a rule the informant does not regard his conception as an estimate； but as certain knowledge。 He does not say； ‘‘I estimate；'' he says； ‘‘It is so。'' Aubert tells how the astronomer Frster had a number of educated men； physicians； etc。； estimate the diameter of the moon。 The estimation varied from 1'' to 8'' and more。 The proper diameter is 1。5'' at a distance of 12''。
It is well known that an unfurnished room seems much smaller than a furnished one； and a lawn covered with snow； smaller than a thickly…grown one。 We are regularly surprised when we find an enormous new structure on an apparently small lot； or when a lot is parcelled out into smaller building lots。 When they are planked off we marvel at the number of planks which can be laid on the sur… face。 The illusions are still greater when we look upward。 We are less accustomed to estimation of verticals than of horizontals。 An object on the gutter of a roof seems much smaller than at a similar distance on the ground。 This can be easily observed if any figure which has been on the roof of a house for years is once brought down。 Even if it is horizontally twice as far as the height of the house； the figure still seems larger than before。 That this illusion is due to defective practice is shown by the fact that children make mistakes which adults find inconceivable。 Helmholtz tells how； as child； he asked his mother to get him the little dolls from the gallery of a very high tower。 I remember myself that at five years I proposed to my comrades to hold my ankles so that I could reach for a ball from the second story of a house down to the court…yard。 I had estimated the height as one…twelfth of its actual magnitude。 Certain standards of under and overestimations are given us when there is near the object to be judged an object the size of which we know。 The reason for the fact that trees and buildings get such ideal sizes on so…called heroic landscape is the artistically reduced scale。 I know that few pictures have made such a devilish impression on me as an enormous landscape； something in the style of Claude Lorraine； covering half a wall。 In its foreground there is to be seen a clerk riding a horse in a glen。 Rider and horse are a few inches high； and because of this the already enormous landscape becomes frightfully big。 I saw the picture as a student； and even now I can describe all its details。 Without the diminutive clerk it would have had no particular effect。
In this connection we must not forget that the relations of magnitude of things about us are； because of perspective； so uncertain that we no longer pay any attention to them。 ‘‘I find it difficult；'' says Lipps；＇1＇ ‘‘to believe that the oven which stands in the corner of the room does not look larger than my hand when I hold it a foot away from my eyes； or that the moon is not larger than the head of a pin； which I look at a little more closely。。。。 We must not forget how we are in the custom of comparing。 I compare hand and oven； and I think of the hand in terms of the oven。'' That is because we know how large the hand and the oven are； but very often we compare things the sizes of which we do not know； or which we can not so easily get at； and then there are many extraordinary illusions。
＇1＇ Die Grundtatsachen des Seelenlebens。 Bonn 1883。
In connection with the cited incident of the estimation of the moon's diameter； there is the illusion of Thomas Reid who saw that the moon seemed as large as a plate when looked at with the unhampered eye； but as large as a dollar when looked at through a tube。 This mistake establishes the important fact that the size of the orifice influences considerably the estimation of the size of objects seen through it。 Observations through key…holes are not rarely of importance in criminal cases。 The underestimations of sizes are astonishing。
｛illust。 caption = FIG。 1。｝
｛illust。 caption = FIG。 2。｝
Arial perspective has a great influence on the determination of these phenomena； particularly such as occur in the open and at great distances。 The influence is to be recognized through the various appearances of distant objects； the various colors of distant mountains； the size of the moon on the horizon； and the difficulties which arial perspective offers painters。 Many a picture owes its success or failure to the use of arial perspective。 If its influence is significant in the small space of a painting； the illusions in nature can easily become of enormous significance； particularly when extremes are brought together in the observations of objects in unknown regions。 The condition of the air； sometimes foggy and not pellucid； at another time particularly clear； makes an enormous difference； and statements whether about distance； size； colors； etc。； are completely unreliable。 A witness who has several times observed an unknown region in murky weather and has made his important observation under very clear skies； is not to be trusted。
An explanation of many sensory illusions may be found in the so…called illusory lines。 They have been much studied； but Zllner＇1＇ has been the first to show their character。 Thus； really quite parallel lines are made to appear unparallel by the juxtaposition of inclined or crossing lines。 In figures 1 and 2 both the horizontal lines are actually parallel； as may be determined in various ways。
＇1＇ Poggendorf's Annelen der Physik； Vol。 110； p。 500； 114； 587； 117； 477。
The same lines looked at directly or backwards seem； in Fig。 1； convex； in Fig。 2 concave。
｛illust。 caption = FIG。 3。｝
Still more significant is the illusion in Fig。 3； in which the convexity is very clear。 The length； etc。； of the lines makes no difference in the illusion。
On the other hand； in Fig。 4 the diagonals must be definitely thicker than the parallel horizontal lines； if those are to appear not parallel。 That the inclination is what destroys the appearance of parallels is shown by the simple case given in Fig。 5； where the distance from A to B is as great as from B to C； and yet where the first seems definitely smaller than the second。
Still more deceptive is Fig。 6 where the first line with the angle inclined inwards seems incomparably smaller than the second with the angle inclined outwards。
｛illust。 caption = FIG 4。｝
All who have described this remarkable subject have attempted to explain it。 The possession of such an explanation might put
｛illust。 caption = FIG。 5。｝
｛illust。 caption = FIG。 6。｝
us in a position to account for a large number of practical difficulties。 But certain as the facts are； we are still far from their _*why_ and _*how_。 We may believe that the phenomenon shown in Figs。 1 and 2 appears when the boundaries of a field come straight up to a street with parallel sides； with the result that at the point of meeting the street seems to be bent in。 Probably we have observed this frequently without being aware of it； and have laid no particular stress on it； first of all； because it was really unimportant； and secondly； because we thought that the street was really not straight at that point。
In a like manner we may have seen the effect of angles as shown in Figs。 5 and 6 on streets where houses or house…fronts were built cornerwise。 Then the line between the corners seemed longer or shorter； and as we had no reason for seeking an accurate judgment we paid no attention to its status。 We simply should have made a false estimate of length if we had been required to judge it。 It is also likely that we may have supposed an actual or suppository line on the side of the gables of a house enclosed by angles of the gables； to be short；but until now the knowledge of this supposition has had no practical va
