Behavioural Set Psychology: Rigidity of Thought and Behaviour

Rigidity in psychology is tied to behavioural set psychology and mental sets. Rigidity can be a learned behavioural trait: patterns of thinking and acting that form through repeated experience and resist pressure to change.

In this article we examine what rigidity is in psychology, how it relates to behavioural set psychology and mental set psychology, how researchers have defined and measured it across more than a century of work, and where the construct sits in the contemporary literature.

A 100-year-old construct

The construct of rigidity has a productive and venerable history in the field of psychology.

Systematic research on rigidity can be traced back to the Gestalt psychologists of the late 19th and early 20th century (Cattell, 1946; Chown, 1959; Lankes, 1915; Luchins & Luchins, 1994; Muller & Schumann, 1898; Spearman, 1927; Stewin, 1983).

An examination of the names associated with much of the early research on rigidity reads like an all-star roster: Raymond Cattell, Else Frenkel-Brunswik, William James, Kurt Lewin, Abraham Luchins, Milton Rokeach, Charles Spearman, and Louis Thurstone all made substantial contributions to the area.

More than 100 years of systematic study of rigidity have produced a large body of research with some clear and established findings. Controversies surrounding several fundamental aspects of rigidity remain.

Although the term rigidity may be somewhat out of vogue among personality and social psychologists today, considerable interest continues in a range of highly related personality variables, such as flexibility, need for closure, and openness to experience. Indeed, every major personality inventory contains a dimension similar to rigidity.

• But what is rigidity?
• How is it measured?
• What are the causes and correlates of resistance to change?

For social psychologists, answers to these questions bear special importance. Social psychologists have always been interested in behaviour change. As presented in the following review, rigidity is the tendency of an individual not to change.

We believe that a conceptual clarification of rigidity, a summary of the tools for measuring rigidity, and an analysis of the correlates of rigidity will be useful for determining the state of knowledge about this important construct.

The contemporary research base

Despite the long history of research on rigidity, the construct continues to attract researchers from a variety of psychological disciplines (D'Aunno & Sutton, 1992; McKelvie, 1990).

An examination of published research reveals that the term rigidity continues to be commonly used by psychological researchers. Between 1967 and 1998 the term rigidity was used in the abstracts or titles of 1,733 published articles contained in the PsycINFO database (revealed through a free-text search of WebSPIRS in 9/98 for the term rigidity). The term continues to be current; between 1990 and 1998 it was used in the abstracts of 494 published studies.

Each of the abstracts was coded for its focus: muscular rigidity, perceptual rigidity, attitudinal rigidity, behavioural rigidity, determinants of rigidity, rigidity as a predictor variable, rigidity of animal behaviour, rigidity in organizational processes, or rigidity of measurement/theory.

Rigidity research appears across a variety of psychological subdisciplines:

• Personality psychology (Viek, 1997)
• Social psychology (Gruber-Baldini, Schaie, & Willis, 1995; O'Connor & Dyce, 1997)
• Cognitive psychology (Alam & Saeeduzzafar, 1991)
• Counselling (Glover, 1994; Mahalik, Cournoyer, DeFranc, Cherry, & Napolitano, 1998)
• Developmental psychology (Chelune & Thompson, 1987; Everett, Thomas, Cote, Levesque, & Michaud, 1991)
• Educational psychology (Corder & Corder, 1974; Freeman, Sawyer, & Behnke, 1997)
• Neuropsychology (Heinrichs, 1990)
• Organisational behaviour (Miller, Droge, & Vickery, 1997; Rosman, Lubatkin, & O'Neill, 1994; VanAllen, 1994)
• Ethology (Toates, 1997)
• Psychopathology (Hellman, Morrison, & Abramowitz, 1987; Lennings, 1994; Rickelman & Houfek, 1995)
• Psychotherapy (Christoph & Li, 1985; Dare et al., 1995; Mizes & Christiano, 1995)

The construct of rigidity has attracted researchers from around the world, with recent articles on rigidity published by psychologists in Africa, China, Eastern Europe, India, Japan, Mexico, Pakistan, Russia, the United States, and Western Europe.

Defining the psychology of rigidity

In her 1959 review, Sheila Chown noted that the construct of rigidity had proved difficult to define. The term had been used to describe mental sets, extreme attitudes, ethnocentrism, stereotypy, lack of flexibility, perseveration, authoritarianism, and the inability to change habits. Chown failed to provide a coherent definition of rigidity, in part because there was no consensus among researchers.

In light of the focal status given her review, this omission is a serious shortcoming.

Early approaches to the study of rigidity treated it as a unidimensional continuum ranging from rigid at one end to flexible at the other. The notion of rigidity as a unidimensional construct dates back to the late 1800s and was later articulated by Spearman (1927), who described it as "mental inertia" (Lankes, 1915; Pinard, 1932). Spearman is widely known for introducing the g factor; less widely known is that he also proposed a p factor (perseveration factor). According to Spearman, g consisted of the amount of mental energy available and p was the inertia of this energy.

Prior to 1960, definitions for rigidity abounded:

• Goldstein's (1943) "adherence to a present performance in an inadequate way"
• Werner's (1946) "lack of variability in response"
• Rokeach's (1948) "inability to change one's set when the objective conditions demand it"
• Buss's (1952) "resistance to shifting from old to new discriminations"

In their comprehensive survey of the literature, Luchins and Luchins (1959) listed 34 factors identified in various studies, many of which were conceptually similar. They ruefully noted that "one investigator seldom relates the factors he promulgates to those in other studies" (p. 94). Clearly, at the time of Chown's review, there was no consensus as to how to define rigidity.

A useful development since 1959 has been Rokeach's The Open and Closed Mind (1960). Summarising the wide range of approaches to the construct, Rokeach defined rigidity as a resistance to change in beliefs, attitudes, or personal habits. The usefulness of this definition is its multidimensional nature.

Rigidity is not simply the perseveration of behaviour on a behavioural task but can be divided into cognitive, attitudinal, and behavioural components.

Rokeach used the term dogmatism to refer to resistance to change in a person's belief system. Rigidity refers to single beliefs (or habits), whereas dogmatism refers to a system of beliefs.

Despite Rokeach's attempt to provide clarification, a 1967 summary of the literature reached a conclusion similar to Chown's: Leach (1967) stated, "A large amount of effort has been devoted to the study of rigidity … yet there is still little agreement as to its identity or its components" (p. 11). Research in the last 42 years has by no means converged on a consensus regarding the nature of rigidity, partly because of the multidimensional nature of the construct.

Rigidity as mental or behavioural set

First, rigidity involves the formation of a mental or behavioural set (Chown, 1959; Rokeach, 1948; Sarmany-Schuller, 1994; Stewin, 1983; Vollhardt, 1990).

By set, we mean a learned mental or behavioural pattern that forms through repeated experience in a given situation (Luchins, 1942; Luchins & Luchins, 1959, 1994). This is the core sense in which rigidity is a learned behavioural trait. The set itself is acquired, not innate, even where genetic and temperamental factors influence the speed and stability of acquisition.

Mental sets are expectations about future events (including attitudes, beliefs, expectancies, and schemas), whereas behavioural sets are patterns of observable responses.

Second, rigidity involves the perseveration of these sets, the continuation of the set in the face of pressure to change (Goldberg, 1986; Goldberg & Tucker, 1979; Luchins & Luchins, 1994; Sandson & Albert, 1984). Pressure to change can come from a variety of sources, including (a) the realisation that the set is no longer effective, efficient, or appropriate for the current situation; or (b) pressure from an external agent indicating that change is desirable.

We define rigidity as the tendency to develop and perseverate in the use of mental or behavioural sets.

Thus, there are two steps in the rigidity process: set formation and set perseveration (Guetzkow, 1951; Taylor & McNemar, 1955). These two steps are positively correlated such that a person who quickly forms a set is likely to perseverate in its use (Luchins & Luchins, 1982). A person who quickly forms a mental set should also be likely to quickly form a behavioural set.

This definition incorporates the historical distinction between structural rigidity and functional rigidity. The tendency to develop a set is similar to structural rigidity; the tendency to perseverate in the use of a set is similar to functional rigidity.

Perseveration and habit

One important distinction is between perseveration and habit.

Habit

A habit is a typical pattern of behaviour: a behavioural set that occurs largely without reflection. Examples include daily routines such as routes to work or driving on the right side of the road in countries where that is the convention.

Perseveration

In and of themselves, habits are not rigid. A behavioural pattern only meets our definition of rigidity when it perseverates in the face of pressure to change.

Consider the case of a U.S. automobile driver who travels to England, where the convention is to drive on the left. If, after several driving excursions, the driver is still unable or unwilling to adapt to the new prevailing rules of the road, this would reflect rigidity, not a habit.

Measuring rigidity

Although the literature suggests some agreement on the definition of rigidity, no universally acknowledged or accepted measurement exists. There has been little research aimed at establishing the relationship among existing techniques (Joshi, 1974). Many researchers, dissatisfied with the available instruments, create idiosyncratic measures of rigidity, reporting only minimal descriptions of materials or procedures.

Chown's review identified 47 measures of rigidity, and many additional measures have been developed since. Some researchers have moved away from the term rigidity and instead adopted labels such as personal need for structure, need for closure, openness, or flexibility.

Eleven measures of rigidity divided into two categories (seven questionnaire measures and four perseveration measures) are summarised below.

Questionnaire measures of rigidity

By far the most widely used procedure for measuring rigidity is to ask respondents to rate statements on a Likert-type scale. These scales are easily administered to many respondents simultaneously and have the advantage of providing estimates for internal reliability.

Breskin Rigidity Test

The Breskin Rigidity Test is based on the Gestalt Laws of Pragnanz and measures individual differences in the tendency to form a perceptual set (Breskin, 1968, 1969; Breskin, Gorman, & Hochman, 1970; Breskin & Rich, 1971). Respondents are presented with pairs of images, one of which has "good form" and the other of which does not. Respondents are asked to select the one they prefer.

Examples of item pairs from the scale include an equilateral triangle (good form) versus an isosceles triangle, or a complete circle (good form) versus an incomplete circle.

Recent research with the scale has found it to be a good predictor of perceptual organisation and to have good internal consistency (Beer, 1989; Cunningham, Ridley, & Campbell, 1988; Maltby & Lewis, 1996).

Several articles in the 1970s suggested the term perceptual rigidity was a misnomer. In examining the relationship between the Breskin scale and performance on standard reversible-figures tasks (the Necker Cube or the Rubin Vase) that require a change in the perceptual set, several studies found nonsignificant effects (Joshi, 1974; Primavera, Simon, & Hochman, 1974). Primavera et al. argued that the Breskin scale measures "obsessive cognitive rigidity" and not "perceptual rigidity."

California Personality Inventory — Flexibility (CPI; Gough & Bradley, 1996)

The flexibility subscale of the CPI was developed to measure rigidity-flexibility of personality unassociated with political ideology. The first version of the scale, known as the Gough Rigidity scale, was incorporated into the CPI in 1956.

People scoring high on flexibility are described as imaginative, spontaneous, and able to adapt to change and the unexpected. They are also described as inconsistent and undependable. People who score low on the scale are described as serious, stubborn, and inflexible.

Factor analyses of the 28 items have revealed a complex pattern. Gough and Bradley reported seven factors from a norm sample of 6,000 people; little published research exists on those factors.

Intolerance of Ambiguity Scale

Budner (1962) defined intolerance of ambiguity as "the tendency to perceive ambiguous situations as sources of threat" and tolerance of ambiguity as "the tendency to perceive ambiguous situations as desirable" (p. 29). The 16-item scale measures individual differences in desire for certainty (Durrheim, 1995). The research literatures on rigidity and intolerance of ambiguity are so closely related that the two constructs are often treated as synonymous.

Need for Closure Scale (NFCS; Kruglanski, Webster, & Klern, 1993)

The 42-item NFCS measures individual differences in preferences for order and structure and the abhorrence of disorder and chaos. The scale measures five correlated subsets labelled preference for structure, discomfort with ambiguity, decisiveness, predictability, and closed-mindedness.

Research by Kruglanski and colleagues confirmed the five-factor structure and demonstrated reasonable predictive ability. The scale distinguishes "artistic types" from "conventional types", predicts individual differences in the tendency to show the primacy effect, is positively correlated with the tendency to commit the fundamental attribution error, and is positively correlated with resistance to persuasion.

Openness to experience

Openness to experience is one of the personality dimensions included in the Five-Factor Model of personality (McCrae, 1996; McCrae & Costa, 1996). Openness is a broad and general dimension that includes a preference for novelty, cognitive complexity, and flexibility. Closedness is manifested in a preference for familiarity, simplicity, and closure.

Personal Need for Structure (PNS; Neuberg & Newsom, 1993, Study 3)

Personal need for structure refers to individual differences in preference for cognitive simplicity and structure. Measured with a 12-item scale, the PNS represents the degree to which people are motivated to structure their worlds in simple and unambiguous ways.

Factor analyses of the scale have revealed two factors labelled Desire for Structure and Response to Lack of Structure. Research suggests that high PNS is associated with a greater tendency to stereotype (Neuberg & Newsom; Schaller, Boyd, Yohannes, & O'Brien, 1995), a greater tendency to categorise new information (Moskowitz, 1993), a tendency to create less complex categories for objects (Neuberg & Newsom, 1993, Study 3), and a tendency to develop mental sets under stressful conditions (Schultz & Searleman, 1998).

Test of Behavioural Rigidity (TBR)

Schaie (1955), in a paper not cited in Chown's (1959) review, distinguished between "motor-cognitive flexibility" and "personality-perceptual flexibility." Schaie reported the results from a factor analysis of eight instruments showing three distinct factors:

1. Psychomotor Speed: the speed with which a person responds to a familiar situation. As this does not measure rigidity per se, it is generally excluded from rigidity reviews.
2. Personality-Perceptual: defined as "ideational inertia" and measured with a series of true-false questions drawn from early self-report scales of mental flexibility (Schaie, Dutta, & Willis, 1991; Schaie & Parham, 1975). This factor reflects an individual's ability to adjust readily to new surroundings. More recently, this factor has been termed "attitudinal flexibility" (see Schaie, 1996).
3. Motor-Cognitive: a person's ability to shift without difficulty from one activity to another, the behavioural aspect of rigidity. An 8-year longitudinal study of rigidity using covariance structural models found support for the identity of unique cognitive and behavioural factors (Schaie et al., 1991).

Summary

Rigidity is a multidimensional construct with more than 100 years of academic study behind it. The construct combines:

1. Set formation: the tendency to develop learned mental and behavioural patterns through repeated experience.
2. Perseveration: the tendency to continue applying those sets in the face of pressure to change.
3. A multidimensional structure: cognitive, attitudinal, and behavioural components, each measurable through different instruments (questionnaires, perseveration tasks).

The literature continues to evolve. Contemporary work increasingly uses related terms (flexibility, need for closure, openness, personal need for structure) to describe the same underlying construct from different angles.

For applied disciplines that depend on changing user behaviour, including conversion rate optimisation, the rigidity construct is a useful framework for understanding why some interface, copy, and offer changes meet resistance even when they are objectively superior.

FAQ

What is rigidity in psychology?
Rigidity is the tendency to develop and perseverate in the use of mental or behavioural sets: learned patterns that resist change even when the situation calls for it. It has cognitive, attitudinal, and behavioural components.

Is rigidity a learned behavioural trait?
Yes. The mental and behavioural sets that produce rigidity are formed through repeated experience in given situations. Genetic and temperamental factors influence the speed of acquisition, but the sets themselves are learned.

How is rigidity measured?
Rigidity is measured through questionnaires (Breskin Rigidity Test, CPI Flexibility, Intolerance of Ambiguity Scale, Need for Closure Scale, Openness to Experience, Personal Need for Structure, Test of Behavioural Rigidity) and through perseveration tasks. No single instrument is universally accepted.

What is the difference between mental set and behavioural set?
Mental sets are expectations about future events: attitudes, beliefs, expectancies, schemas. Behavioural sets are patterns of observable responses. Both are learned through repeated experience and both can perseverate.

What is the difference between perseveration and habit?
A habit is a typical pattern of behaviour that occurs without reflection. It only becomes rigidity when it perseverates in the face of pressure to change.

Who introduced rigidity to academic psychology?
The construct dates back to the Gestalt psychologists of the late 19th and early 20th century. Spearman (1927) described rigidity as "mental inertia." Sheila Chown's 1959 Psychological Bulletin review and Milton Rokeach's The Open and Closed Mind (1960) are the foundational modern texts.