斯金纳是一位久负盛名的心理学家，堪称行为主义之父，他是著名的“斯金纳箱”的发明者，此外他还出版了 10 多本著作，发表了 70多篇科学论文。斯金纳的理论用一句简单的话来概括就是：在任一特定的情况下，你的行为都很可能伴随着某种结果，比如得到赞扬、报酬或解决问题后的满足感，那么随后在类似的情况下，你很可能重复这一行为；这些结果被称为强化。如果你的行为伴随着另一种结果，比如疼痛或尴尬，那么你在以后的相似情况下就很少会重复这种行为；这些结果被称为“惩罚”。
在斯金纳的众多研究中，有一篇题为《鸽子的迷信行为》，这篇文章不仅题目幽默，而且通过这个有趣的研究，我们不仅能够清楚的认识斯金纳的基本理论，他的研究行为方式、方法，还能对我们都熟悉的“迷信”现象进行一种斯金纳式的解释。
理论假设
人们总是会有这样那样的迷信行为，比方说，忌讳从梯子下走过，忌讳踩到裂缝等等。很多人不愿意承认这一点，但是某些时候人们是会因为迷信而做某些事情。斯金纳认为，人们这样做的原因是他们相信或推测在迷信行为和某些被强化的结果之间存在联系，即便是实际情况下两者并不相关。所以，斯金纳说了下面的话“如果你认为这是人类特有的行为，那么我将给你一只迷信的鸽子。”
实验方法
斯金纳在此项研究中使用了“斯金纳箱”，但做了重要的变化：即为了研究迷信行为，食物分发器被设定为每隔 15秒落下食丸，不管动物当时在做什么。可以看到这便产生了非关联性强化。换句话说，不管动物做了什么，每隔 15 秒它将得到一份奖励。
研究中的被试是 8只鸽子。连续几天对这些鸽子喂少于他们正常进食量的食物，以便在测试时，它们处于饥饿状态。由此增强寻找食物的动机（这增加了强化的效果）。让每只鸽子每天在实验箱里待几分钟，对其行为不作任何限制。在这期间，每个15 秒强化自动出现。几天后，两个独立的观测者记录了鸽子在箱中的行为。
实验结果
斯金纳在报告中写道：“ 8 只鸽子中的 6 只产生了非常明显的反应，两名观察者得到了完全一致的记录。一只鸽子形成了在箱子中逆时针转圈的条件反射，在两次强化之间转2 － 3圈；另一只反复将头撞向箱子上方的一个角落；第三只只显现出一种上举反应，似乎把头放在一根看不见的杆下面并反复抬起它。还有两只鸽子的头和身体呈现出一种摇摆似的动作，它们头部前伸，并且从右向左大幅度摇摆，接着再慢慢的转过来，它们的身子也顺势移动，动作幅度过大时还会向前走几步。还有一只鸽子形成了不完整的啄击或轻触的条件反应，动作直冲地面但并不接触。”
上述的行为都是在建立条件反射前未曾观测到的。实际上新的行为和鸽子得到食物毫无联系。然而，它们表现的就好像行为会产生食物似的；也就是说，它们变得迷信了。
接下来，斯金纳想知道如果两次强化之间的间隔被拉长了，又会发生什么。他用了一只摇头的鸽子，然后把两次投放食丸的时间间隔慢慢增加到 1分钟。这时，鸽子表现的更加精力充沛，直到最后在两次强化间的 1 分钟内，这只鸽子像在表演一种舞蹈（好像一种“鸽子食物舞”）。
最后是消除鸽子的这种新行为。这意味着在测试箱中的强化不再出现。这时，迷信行为逐渐消退，直到完全消失。然而，值得注意的是，这只“跳舞”的鸽子在完全消退前的这种反应次数超过了1 万次。
讨论
在实验中斯金纳得到了 6只迷信的鸽子。然而，他对这一成果的解释却极为谨慎：“这一实验可以说是证明了一种迷信。鸽子行为的依据是行为和食物之间的因果关系，虽然这种联系实际上并不存在。”
迷信难以消退的原因可以从那只在行为消除前跳了 1万多次舞的鸽子那儿去寻找。当某种行为只是偶然的被强化一次，它就变得非常难以消除。这是因为人们的期望值很高，期望迷信行为会产生强化的后果。你能想象，如果每种联系每次出现，然后突然消失，那么行为就会很快停止，然而，对人类而言，偶然的强化通常要过很长时间才能发生，因此迷信行为常常持续一生。
结论
迷信无处不在，从心理学角度看迷信是不健康的吗？绝大多数心理学家相信，尽管从定义上讲，迷信行为并不会导致你想要的结果，但它们还是有积极的功能。当一个人身处困境时，迷信行为经常能产生力量，不再失控。从事危险职业的人比其他人更加迷信。有时候，由迷信行为带来的力量感和控制感能降低焦虑、增强自信和信心，并提高成绩。
'SUPERSTITION' IN THE PIGEON
B. F. Skinner
Indiana University
First published in Journal of Experimental Psychology, 38, 168-172.
To say that a reinforcement is contingent upon a response may mean nothing more than that it follows the response. It may follow because of some mechanical connection or because of the mediation of another organism; but conditioning takes place presumably because of the temporal relation only, expressed in terms of the order and proximity of response and reinforcement. Whenever we present a state of affairs which is known to be reinforcing at a given drive, we must suppose that conditioning takes place, even though we have paid no attention to the behavior of the organism in making the presentation. A simple experiment demonstrates this to be the case.
A pigeon is brought to a stable state of hunger by reducing it to 75 percent of its weight when well fed. It is put into an experimental cage for a few minutes each day. A food hopper attached to the cage may be swung into place so that the pigeon can eat from it. A solenoid and a timing relay hold the hopper in place for five sec. at each reinforcement.
If a clock is now arranged to present the food hopper at regular intervals with no reference whatsoever to the bird's behavior, operant conditioning usually takes place. In six out of eight cases the resulting responses were so clearly defined that two observers could agree perfectly in counting instances. One bird was conditioned to turn counter-clockwise about the cage, making two or three turns between reinforcements. Another repeatedly thrust its head into one of the upper corners of the cage. A third developed a 'tossing' response, as if placing its head beneath an invisible bar and lifting it repeatedly. Two birds developed a pendulum motion of the head and body, in which the head was extended forward and swung from right to left with a sharp movement followed by a somewhat slower return. The body generally followed the movement and a few steps might be taken when it was extensive. Another bird was conditioned to make incomplete pecking or brushing movements directed toward but not touching the floor. None of these responses appeared in any noticeable strength during adaptation to the cage or until the food hopper was periodically presented. In the remaining two cases, conditioned responses were not clearly marked.
The conditioning process is usually obvious. The bird happens to be executing some response as the hopper appears; as a result it tends to repeat this response. If the interval before the next presentation is not so great that extinction takes place, a second 'contingency' is probable. This strengthens the response still further and subsequent reinforcement becomes more probable. It is true that some responses go unreinforced and [p. 169] some reinforcements appear when the response has not just been made, but the net result is the development of a considerable state of strength.
With the exception of the counter-clockwise turn, each response was almost always repeated in the same part of the cage, and it generally involved an orientation toward some feature of the cage. The effect of the reinforcement was to condition the bird to respond to some aspect of the environment rather than merely to execute a series of movements. All responses came to be repeated rapidly between reinforcements -- typically five or six times in 15 sec.
The effect appears to depend upon the rate of reinforcement. In general, we should expect that the shorter the intervening interval, the speedier and more marked the conditioning. One reason is that the pigeon's behavior becomes more diverse as time passes after reinforcement. A hundred photographs, each taken two sec. after withdrawal of the hopper, would show fairly uniform behavior. The bird would be in the same part of the cage, near the hopper, and probably oriented toward the wall where the hopper has disappeared or turning to one side or the other. A hundred photographs taken after 10 sec., on the other hand, would find the bird in various parts of the cage responding to many different aspects of the environment. The sooner a second reinforcement appears, therefore, the more likely it is that the second reinforced response will be similar to the first, and also that they will both have one of a few standard forms. In the limiting case of a very brief interval the behavior to be expected would be holding the head toward the opening through which the magazine has disappeared.
Another reason for the greater effectiveness of short intervals is that the longer the interval, the greater the number of intervening responses emitted without reinforcement. The resulting extinction cancels the effect of an occasional reinforcement.
According to this interpretation the effective interval will depend upon the rate of conditioning and the rate of extinction, and will therefore vary with the drive and also presumably between species. Fifteen sec. is a very effective interval at the drive level indicated above. One min. is much less so. When a response has once been set up, however, the interval can be lengthened. In one case it was extended to two min., and a high rate of responding was maintained with no sign of weakening. In another case, many hours of responding were observed with an interval of one min. between reinforcements.
In the latter case, the response showed a noticeable drift in topography. It began as a sharp movement of the head from the middle position to the left. This movement became more energetic, and eventually the whole body of the bird turned in the same direction, and a step or two would be taken. After many hours, the stepping response became the predominant feature. The bird made a well defined hopping step from the right to the left foot, meanwhile turning its head and body to the left as before.
When the stepping response became strong, it was possible to obtain a mechanical record by putting the bird on a large tambour directly connected with a small tambour which made a delicate electric contact each time [p. 170] stepping took place. By watching the bird and listening to the sound of the recorder it was possible to confirm the fact that a fairly authentic record was being made. It was possible for the bird to hear the recorder at each step, but this was, of course, in no way correlated with feeding. The record obtained when the magazine was presented once every min. resembles in every respect the characteristic curve for the pigeon under periodic reinforcement of a standard selected response. A well marked temporal discrimination develops. The bird does not respond immediately after eating, but when 10 or 15 or even 20 sec. have elapsed it begins to respond rapidly and continues until the reinforcement is received.
(图略)
Fig. 1. 'Reconditioning' of a superstitious response after extinction. The response of hopping from right to left had been thoroughly extinguished just before the record was taken. The arrows indicate the automatic presentation of food at one-min. intervals without reference to the pigeon's behavior.
In this case it was possible to record the 'extinction' of the response when the clock was turned off and the magazine was no longer presented at any time. The bird continued to respond with its characteristic side to side hop. More thanl0,000 responses were recorded before 'extinction' had reached the point at which few if any responses were made during a 10 or 15 min interval. When the clock was again started, the periodic presentation of the magazine (still without any connection whatsoever with the bird's behavior) brought out atypical curve for reconditioning after periodic reinforcement, shown in Fig. 1.The record had been essentially horizontal for 20 min. prior to the beginning of this curve. The first reinforcement had some slight effect and the second a greater effect. There is a smooth positive acceleration in rate as the bird returns to the rate of responding which prevailed when it was reinforced everymin.
When the response was again extinguished and the periodic presentation of food then resumed, a different response was picked up. This consisted of a progressive walking response in which the bird moved about the cage. [p. 171]The response of hopping from side to side never reappeared and could not, of course, be obtained deliberately without making the reinforcement contingent upon the behavior.
The experiment might be said to demonstrate a sort of superstition. The bird behaves as if there were a causal relation between its behavior and the presentation of food, although such a relation is lacking. There are many analogies in human behavior. Rituals for changing one's luck at cards are good examples. A few accidental connections between a ritual and favorable consequences suffice to set up and maintain the behavior in spite of many unreinforced instances. The bowler who has released a ball down the alley but continues to behave as if he were controlling it by twisting and turning his arm and shoulder is another case in point. These behaviors have, of course, no real effect upon one's luck or upon a ball half way down an alley, just as in the present case the food would appear as often if the pigeon did nothing -- or, more strictly speaking, did something else.
It is perhaps not quite correct to say that conditioned behavior has been set up without any previously determined contingency whatsoever. We have appealed to a uniform sequence of responses in the behavior of the pigeon to obtain an over-all net contingency. When we arrange a clock to present food every 15 sec.,we are in effect basing our reinforcement upon a limited set of responses which frequently occur 15 sec. after reinforcement. When a response has been strengthened (and this may result from one reinforcement), the setting of theclock implies an even more restricted contingency. Something of the same sort is true of the bowler. It is not quite correct to say that there is no connection between his twisting and turning and the course taken by the ball at the far end of the alley. The connection was established before the ball left the bowler's hand, but since both the path of the ball and the behavior of the bowler are determined, some relation survives. The subsequent behavior of the bowler may have no effect upon the ball, but the behavior of the ball has an effect upon the bowler. The contingency, though not perfect, is enough to maintain the behavior in strength. The particular form of the behavior adopted by the bowler is due to induction from responses in which there is actual contact with the ball. It is clearly a movement appropriate to changing the ball's direction. But this does not invalidate the comparison, since we are not concerned with what response is selected but with why it persists in strength. In rituals for changing luck the inductive strengthening of a particular form of behavior is generally absent. The behavior of the pigeon in this experiment is of the latter sort, as the variety of responses obtained from different pigeons indicates. Whether there is any unconditioned [p. 172] behavior in the pigeon appropriate to a given effect upon the environment is under investigation.
The results throws some light on incidental behavior observed in experiments in which a discriminative stimulus is frequently presented. Such a stimulus has reinforcing value and can set up superstitious behavior. A pigeon will often develop some response such as turning, twisting, pecking near the locus of the discriminative stimulus, flapping its wings, etc. In much of the work to date in this field the interval between presentations of the discriminative stimulus has been one min. and many of these superstitious responses are short-lived. Their appearance as the result of accidental correlations with the presentation of the stimulus is unmistakable.
(Manuscript received June 5, 1947)
