On functional fixedness

Some critical remarks

JENSEN, J. On functional fixedness. Some critical remarks. Scand. J. PsychoL, 1960, J, 157-162.—The interpretation of functional fixedness as a fixation of behavior or inhibiting of behavior tendencies is challenged. As an alternative is proposed 'perceptual emphasis' in which the effect of past experience with the use of objects is viewed in agreement with van de Geer as a change in the perception of the objects. Some recent experiments are reviewed in the light of this phenomenological interpretation.

Ever since Duncker's coining of the term Funktionalgebundenheit or 'functional fixedness', this theme has occupied a central place in the study of human problem solving. A study of the literature around this subject seems, however, to reveal a certain one-sidedness in the interpretation of the effects of this special kind of past experience. It seems as if the concept of'fixedness' is used more or less with a negative connotation and is specifically related to overt behavior or inhibited behavior tendencies.
This interpretation, however, raises certain difficulties in the evaluation of some experimental results. The following remarks try to point out some advantages in linking the interpretation more closely to the perceptual sphere. It is not my intention to draw any sharp and unjustified distinction between behavior and perception; I only wish to call attention to the fact that a change of emphasis in the interpretation may be a possibility of some interest.

EXPERIMENTAL METHODS
Flavell et al. (1958) has given an excellent introduction to the methods used in the study of functional fixedness. He distinguishes between two different methodological paradigms.
In the first place he mentions the 'one-object' paradigm which Duncker used, but which has also been used in later investigations. Here two groups of subjects are given a problem whose difficulty consists in the fact that a well-known object is to be used in a novel and unusual way in the solution of the problem.
One group—the control group—is given no special experience with the well-known object before the critical problem. The experimental group, however, is given the opportunity to react to the object in a context where its usual function is accentuated. The functional fixedness expresses itself by a smaller number of solutions in the experimental group or by longer times for solution in this group—or possibly by both.
In the second place we have the 'two-object' paradigm, which is essentially different from the first one. At first two objects A and B (each with its own usual function) are equated by means of a control group which is given a problem demanding the use of either of the objects in a novel function. The problem is rather simple and, if necessary, help is given so that everybody arrives at a solution. The two objects are considered equivalent for the given purpose if about 50 per cent of the control group choose one, and 50 per cent choose the other in their solutions. Then the same problem is given to two different groups of subjects; one of these groups has had the usual function of A accentuated in advance, the other one has had the usual function of B accentuated. The functional fixedness, in this case, expresses itself in a tendency on the part of the subjects to use that object in the critical problem whose usual function has not been accentuated. The 'two-object* paradigm was first used by Birch & Rabi-nowitch (1951).
While functional fixedness in the first case is a matter of solution vs. non-solution of a rather difficult problem, it is, in the second case, a matter of choice of objects or means for the solution of a comparatively easy problem. It is to be expected that the last method is the one that gives the purest measure of functional fixedness. In the first method a difficult problem is used and the non-solution of this problem may very well be attributable to other factors than functional fixedness.

EXPERIMENTS ON FUNCTIONAL FIXEDNESS
In 1952 Adamson repeated some of Duncker's experiments on functional fixedness. Duncker's well-known hypothesis was that the earlier use of an object in a function different from the one required for the solution of a given problem will inhibit the discovery of this new function. Duncker's conclusions, however, are based on data from only 14 subjects and Adamson found this material too limited to be accepted as reliable evidence. He therefore repeated the experiment with 57 subjects, using three of the practical problems which Duncker used.
Duncker used the number of solutions in a group of subjects as a measure of the success of the group. This measure cannot be applied to Adamson's subjects who apparently are more able than Duncker's; by far the greater part of the subjects solves the problems. Adamson is led to choose another measure, namely the time required for the solution. It appears that the experimental group, i.e. the 'functionally fixed' group, solves the problems significantly slower than the control group. One of the problems is so difficult that the number of solutions may be used as a measure. The expected difference between the groups appears also on this measure.
Birch & Rabinowitch (1951) criticize the method in investigations like these. Their chief objection is that the particular situation wherein the first function of the object is accentuated ('fixed') is a part of the whole problem-solving situation. A box, for example, does not only function as a container but it contains some of the very material which has to be used in the solution; and the function of a drill is not only accentuated by drilling, but by drilling holes for the actual hooks which are required in the solution. The consequence of this may be that other things than just functional fixedness come into play and limit the new application of the object, e.g. self-formulated directions regarding what is or is not allowed, and the fact that the object may drop out of the field of interest, having been used in a finished (part) task. They stress as a further objection that the actual material to be used by the two groups may not be equally suitable for the solution. If the relevant objects in the experimental group are 'objectively less adequate' than the objects in the control group, then the latter group will be favoured in advance. Unfortunately no examples are given, and the objection does not appear quite clear. The meaning might be that a filled matchbox is 'objectively less adequate' as a shelf than an empty one, but it is difficult to distinguish this description in terms of adequacy from the description in terms of accentuating the function of the box as a container—which is the very fact whose effect is to be investigated in the experiment.
Viewed in connection with the first objection we may, however, get a notion of what, according to Birch & Rabinowitch, Duncker ought to have done. The accentuating of the function should have taken place in a situation wholly independent of the later problem context so that the two groups, in terms of the stimulus situation, can be said to solve the same problem. For Duncker's box problems this would mean that both groups are given the same problem and
the same material, including an empty box. Only the one group has, in advance and in a wholly different context, had accentuated the function of the box as a container. This would have been a purer example of the one-object design. Birch & Rabinowitch might have used this design but they preferred a two-object design instead.
As the critical problem they use a modified form of Maier's Two-String problem in which the subject has to get hold of two strings suspended so far from each other that the second string cannot be reached while the first one is still held. The only solution accepted in this case is the pendulum solution, in which an object is fastened to one string which is set swinging, while the other one is reached. Furthermore the solution involves the use of two objects on the table in front of the subject: a switch and a relay.
The 25 subjects are divided into three groups. One group has in advance of the critical problem solved another problem, namely to construct an electrical circuit by means of the switch. The second group solves the same problem, except that the relay has to be used. These two objects have exactly the same function, i.e. to turn on and turn off the current. The third group is a control group and solves the critical problem only.
The results show clearly the effect of the experience with the object in the first problem. In the experimental groups 10 out of 10 and 7 out of 9 subjects solve the critical problem by means of the object that has not been used in the pre-problem. In the control group the two objects are chosen equally frequently.
Other recent investigations have tried to view functional fixedness in relation to other variables. Adamson & Taylor (1954) ask whether functional fixedness is dependent upon the time which passes between the first ('function-fixing') problem and the second problem in which the relevant objects must be used. The experimental findings seem to indicate that even if certain experiences change our perception and behavior in relation to the environmental objects, these effects are quite limited in time—things slip back into their old order.

FUNCTIONAL FIXEDNESS VS. PERCEPTUAL EMPHASIS
In all these investigations can be seen a common feature which van de Geer (1957) has pointed out. The function which is accentuated before the solution of the critical problem is in every case the usual, well-known function of the object, the purpose for which it was originally designed. Van de Geer has studied what happens if the first required function is a novel one and the critical function is the usual one.
The method is simple and clever. The critical objects are a screwdriver and a spanner. There are two problems, (i) A wooden block is to be separated into its two parts. This requires that a screw is loosened; the head of the screw is six-sided but has a normal slot at the same time. So it may be loosened equally well with a screwdriver and a spanner. (2) Maier's Two-String problem in which one of the tools may be used as a weight for the pendulum solution.
Group A starts with problem i, i.e. with the normal functions of the objects, and is then supposed to use them in the novel function in problem 2. Group B starts with problem 2.
The experiment leads to the very interesting results that while group A fully confirms the earlier experiments, group B displays no tendency to the effect that the use of an object m an unusual function inhibits a later use of the same object in its originally designated normal function.
Van de Geer tries to give a phenomenological interpretation of this finding. It seems unnecessary to suppose a 'fixation' to a specific function just because an object has once been used in a certain manner. It is rather to be assumed that the use of an object in its normal and usual function influences the perception of this object so that it is even more com-pellmgly experienced as a tool with a specific designation. Its material properties recede

into the background in favour of its use. The same thing does not happen if the object is used in a novel and unusual fashion. One's knowledge of the thing and of its normal use is so firmly established that an accidental application of certain less essential material properties will not result in much of a change in one's relation to it. As soon as a situation is presented which appeals to the normal function of the object it regains its tool character— slips back into order again.
These last remarks, which go farther than van de Geer may like to follow, apply only to a special class of well-known objects. Of general importance, however, is the stress upon the perceptual effects of the past use of an object. Evidence of this is found in the study by Birch & Rabinowitch already mentioned. After the experiment the subjects were questioned about their reasons for choosing the particular object as a weight in the pendulum solution. The answers showed that not only the problem-solving behavior, but also the perception of the material is influenced by the past experience of it. Regardless of whether the switch or the relay was used in the pendulum construction, the subjects experienced the chosen object as particularly well suited to the purpose: it was heavier, easier to fasten, etc.
In accordance with a phenomenological interpretation of the effect of past experience with the use of objects it might perhaps be a good idea to substitute, or at least supplement the formulation in terms of behavioral fixation by a formulation in terms of perceptual organisation or accent. Over against the expression 'functional fixedness' might be put 'perceptual emphasis' as a description of the effect of the accentuation of functional properties of things. Or possibly we might use 'functional fixedness' to refer exclusively to the observable event and 'perceptual emphasis' to refer to the underlying psychological process.

'PERCEPTUAL EMPHASIS' PUT TO USE
Unlike most earlier investigators Flavell et al. (1958) has worked with the accentuation of a number of unusual functions preceding the critical problem. His purpose was to study whether the functional fixedness will decrease with an increase in the number of experiences with unusual applications of an object.
Flavell's material is a switch and a relay and the Two-String problem. 144 subjects are divided into five experimental groups and one control group. The control group solves the Two-String problem having had no past experience with the critical objects. The experimental groups all solve a problem where the switch is used in its normal function, as part of an electrical circuit. One group solves only this problem, while the other four groups solve respectively i, 2, 3, or 4 other problems where the switch must be used in different unusual ways, e.g. to support something, or to act as a ruler.
The results most nicely confirm the hypothesis. The experimental group that has had only the usual function accentuated displays a marked functional fixedness: only three out of the 24 subjects use the 'fixated' object in the pendulum solution of the Two-String problem. In the other four groups which have had accentuated i, 2, 3, and 4 unusual functions, the 'fixated' object is used by respectively 8, 9, 13, and 12 subjects out of groups of 24 subjects. This means that the fixedness of the accentuated usual function decreases, as a greater number of unusual functions is accentuated.
Flavell speaks of functional fixedness in the same 'negative' manner as, for instance, Dunc-ker did, i.e. he considers it an inhibition of alternative functions. This fact is also expressed by his speaking of the unusual functions as 'liberating functions'.
Viewed in terms of the 'fixedness interpretation' it is difficult to see how certain functions can be considered 'liberating'. In principle these functions should also become fixated and inhibit the application of the object in other functions than those just accentuated. Further, it would be impossible to predict whether the fixedness would be greater or smaller according to the fixation of many or a few functions.
Viewed in terms of perceptual emphasis, this effect, by Flavell somewhat inconsistently called 'liberating', may be more easily understood and predicted. Along with the usual function, which is already the dominant property of the perceived object, some other functions are accentuated. Taken singly, these unusual functions are relatively unimportant features of the perceived object, and have no chance of weakening the dominant property, i.e. the usual function, of the object very much. Taken together, however, they may accentuate a quite different, and more general property of the object, namely a certain flexibility or variability in its possible uses. This general property is what is favoured over the dominant function, and this makes the subject more liable to use the object in other functions than the usual one.
According to Flavell's interpretation it is to be expected that the subject's use of switch and relay will approach the same relative frequencies as in the control group as the inhibiting functional fixedness of the switch is weakened by the novel uses. That the switch should in any way be favoured over the relay is inconceivable; after all, only the switch was used in the pre-experience with the electrical circuit problem. According to the interpretation in terms of perceptual emphasis, however, it would not be surprising if the many novel applications of the switch favoured this particular object in the critical problem where another unusual application is demanded.
Looking at Flavell's data a slight tendency in this direction does appear. In the control group, which must be the basis for the comparison, 40 per cent chose the switch. After three and four unusual applications of the switch 54 and 50 per cent respectively of these two experimental groups chose this object for the solution of the critical problem. The tendency is probably not statistically significant, but it is quite unexpected when we think in terms of 'fixedness', while it falls in line with an interpretation in terms of perceptual emphasis.

CONCLUDING REMARKS
The preceding discussion questions the value of speaking of the effects of this particular kind of past experience in terms of concepts like fixation or inhibition. What happens may rather be considered in a positive way as an accentuation which results in certain changes in the perception of things. The already dominant functional properties of perceived objects can be more easily accentuated, while the accentuation of less important minor features is not liable to result in much of a change in our stable notions of well-known things.
It is easy to suggest experiments that might cast further light upon this. In the first place we lack an investigation of objects that have two (or more) equally usual functions. Will an accentuation of one function force the other into the background? In the second place we lack further experiments in which unusual functions are demanded both in the pre-problem and in the critical problem. Let us compare these two kinds of experiments in the light of the alternative interpretations.
In terms of functional fixedness we must expect the smaller effect in the experiment with the usual functions because the past experience with the required 'novel' (but also usual) function is so extensive already that it will have no difficulty in asserting itself against the previously accentuated one. The greater effect, however, has to be expected in the second experiment, where, in a whole repertoire of unusual functions, a single one is accentuated, so that another unusual function has to compete with the fixation partly on the usual function, partly on the accentuated unusual one.
If we think of the effect as a change in perception resulting from the accentuation of a certain use of an object, we shall expect the greater effect in the first experiment because an accentuation should influence an already dominant aspect of perception most. On the other hand, the effect in the second experiment will probably be smaller as the benefit of the accentuation of a minor perceptual property is very small compared to the dominance of the usual function. The perception of the object not being appreciably changed, it is hardly to be expected that the difficulty of finding an unusual function will be appreciably greater in the critical problem than in the pre-problem.
The question may be put whether it makes any real difference if one speaks of perceptual emphasis instead of functional fixedness, so long as this special effect of past experience in any case has to express itself through overt behavior in order to be demonstrated.
Now, in the first place, it seems as if certain inconsistencies in the interpretation of the experiments mentioned may be removed. Secondly, we have seen that the expected outcome of certain experiments will change to the opposite if an interpretation in terms of a fixation of functions is changed to an interpretation in terms of perceptual emphasis.
Thirdly, the choice of interpretation may have certain methodological consequences. Hitherto it seems to have been implicitly accepted that past experience with the use of objects must express itself in behavior, i.e. in the solving of problems or in the choice of objects for solution. By shifting the emphasis from behavior to perception a fertile temptation is provided to give the phenomenological approach a trial in the study of these aspects of problem solving. The work of Saugstad (1955, 1958), Saugstad & Raaheim (1957, 1959), and Raaheim (1959) may perhaps be seen as pointing in this direction.

REFERENCES

ADAMSON, R. E. (1952). Functional fixedness as related to problem solving: a repetition of three experiments. J. exp. Psychol., 44, 288-291.

ADAMSON, R. E., and TAYLOR, D. W. (1954). Functional fixedness as related to elapsed time and to set. J. exp. Psychol., 47, 122-126.

BIRCH, H. G., and RABINOWITCH, H. S. (1951). The negative effect of past experience on productive thinking. JP. exp. Psychol., 41, 121—125

FLAVELL, J. H., COOPER, A., and LOISELLE, R. H. (1958). Effect of the number of pre-utilization functions on functional fixedness in problem solving. Psychol. Rep., 4, 343-350.

GEER, J. P. VAN DE (1957). A Psychological Study of Problem Solving. Haarlem: de Toorts.

RAAHEIM, K. (1959). The ability to name functions for common objects. Nord. Psykol. n, 215-224. (& Acta Psychol. i6y 267-276).

SAUGSTAD, P. (1955). Problem solving as dependent on availability of functions. Brit. J. Psychol., 46, 191-198.

—  (1958). Availability of functions. A discussion of some theoretical aspects. Acta Psychol., 13, 384-400 (& Nord. Psykol., 10, 216-232).

SAUGSTAD, P., and RAAHEIM, K. (1957). Problem solving and availability of functions. Acta Psychol. 13, 263-278 (& Nord. Psykol., 9, 205-220).

—  (1959).  Problem solving and  availability of functions in children. Acta Psychol., 16, 45-48 (& Nord. Psykol., n, 45-58).

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