Biological Preparedness

Biological preparedness is Seligman’s idea that evolution has made some associations far easier for a species to learn than others, so classical conditioning itself is shaped by an organism’s evolutionary history, not just by how often a stimulus and response are paired.

Background

Definition

Biological preparedness is the idea that organisms are biologically predisposed to quickly learn associations between stimuli, responses, and reinforcers (Seligman, 1971).

This quick learning reflects an organism’s fit with genetic traits that evolved to increase the species’ chances of survival. The bias is real.

People may be averse to foods associated with gastrointestinal illness, such as rotting meat, even if they have never eaten them before.

Seligman suggested that humans are biologically prepared to develop certain phobias rather than others because those fears were adaptive in our evolutionary past.

The pattern is not random.

Individuals who avoided snakes and high places, for example, were more likely to survive and pass on their genes than those who did not. This is not an accident of learning.

Preparedness theory remains one of the most influential accounts of why particular phobias exist (Åhs et al., 2018).

Historical Background

Martin E. P. Seligman (1971) proposed the preparedness theory of fears and phobias in his article Phobias and Preparedness.

The paper broke from traditional conditioning theories of fear.

It inspired a line of research integrating evolutionary theory with learning theory that continues today (McNally, 2016). This research spawned adjacent theories of selective sensitization, expectancy, and nonassociative accounts.

Seligman trained first.

He specialized in animal learning and motivation as an experimental psychologist. He later acquired clinical training, which expanded his reach into psychopathology. His best-known later contributions include the learned helplessness theory of depression (Seligman, 1975) and his work in positive psychology (Seligman and Csikszentmihalyi, 2000).

Clinical work followed.

Seligman used preparedness theory to make testable phenomena that traditional conditioning theories could not explain (McNally, 2016).

Prior to Seligman’s work, there was a growing emphasis on phylogenetics, the study of evolutionary relationships between species, in learning and conditioning research. John Garcia’s taste-aversion research was part of this shift.

Garcia found that rats rapidly learn to avoid a sweetened taste after it is followed by radiation-induced gastric distress. They do not learn this aversion as readily when the same taste is instead followed by a food stock.

The pattern held.

Garcia and Koelling (1967) invoked “natural selection” to explain the difference. Taste cues, they argued, were readily linked to gastrointestinal distress. Audiovisual cues, by contrast, were more readily linked to footshock-induced pain (McNally, 2016).

Seligman adopted Garcia and Koelling’s evolutionary reasoning to argue that evolution shapes which behaviors organisms learn most readily. His article went on to shape the study of anxiety disorders, and laboratory experiments testing preparedness theory soon followed.

Preparedness Continuum

Before preparedness, most learning theories assumed equipotentiality: any stimulus could be linked to any response or outcome with roughly equal ease. Any cue would do.

The laws of learning, on this view, were the same for every species.

This was the assumption behind Watson’s claim, dramatised by the Little Albert study.

A fear, on this view, could be conditioned to almost any object simply by pairing it with a frightening noise. Preparedness overturned this idea.

Seligman (1970) replaced the flat, equal-odds picture with a continuum of preparedness. Any potential association can be placed somewhere along it, according to how much training an organism needs to learn it. The continuum has three regions.

• Prepared associations: closely tied to survival, learned in as little as a single trial.
• Unprepared associations: the broad middle band, learned only through repeated pairings.
• Contraprepared associations: run against a species’ evolved tendencies, learned with great difficulty or not at all.

Prepared Associations

Prepared behaviours are closely tied to survival and are acquired with very little training, often in a single trial. Learned food and water aversions are the clearest case.

An animal that samples a novel food and later falls ill will avoid that food afterwards, having learned the association from a single exposure, across a delay of hours.

This speed makes sense. An organism that needed many trials to learn “this food is poison” would, in the wild, be dead before the lesson was complete.

Prepared learning is also unusually durable. Once formed, it resists extinction far more strongly than an ordinary conditioned response does.

The strength of a prepared association tracks the cost of getting it wrong. The more dangerous a mistake would have been for an ancestor, the faster and more permanently the lesson sticks.

Unprepared Associations

Unprepared associations sit in the broad middle of the continuum. They are neither favoured nor opposed by an animal’s evolutionary history, so they are learned at the ordinary rate, through repeated pairings.

Most tasks studied in the conditioning laboratory fall here, such as pressing a lever for a food pellet or salivating to a tone.

Seligman (1970) noted this. Most laboratory learning sits in this unprepared middle band.

The general laws of learning drawn from such experiments therefore describe an unrepresentative slice of everything an organism can learn. The laws are not wrong on their own terms. They are simply local: they describe the flat middle of the learning landscape and say nothing about its peaks and valleys.

This is why the continuum matters. A science built only on the unprepared middle band would miss both ends of it entirely.

Contraprepared Associations

The far end looks very different.

Contraprepared behaviours sit at the far end of the continuum. They run contrary to an animal’s natural, evolved tendencies, so they are learned only with great difficulty, sometimes never, no matter how much training is given.

A pigeon can be trained in minutes to fly between perches to avoid a shock. Training the same pigeon to peck a disc for the same reason rarely works. Pecking is not defensive behaviour.

It is food-related behaviour, with no place in the pigeon’s repertoire of self-protection. This is contraprepared learning.

Contraprepared associations are the mirror image of prepared ones, and they make the continuum a genuine prediction rather than a mere description.

The same reinforcer that shapes one response effortlessly can fail completely to shape another. The pattern is set by a species’ evolved behavioural biology, not by the reinforcement schedule used.

Biological Preparedness Working With Classical Conditioning

The most prominent researcher to test preparedness with classical conditioning was the Swedish psychophysiologist Arne Öhman.

Other studies complicate the picture further. Simple verbal instructions can quickly diminish fear responses to fear-relevant stimuli (Dawson, Schell, & Tweddle-Banis, 1986). Others have failed to replicate Öhman’s original resistance-to-extinction finding at all (Foa & McNally, 1986).

McNally and Reiss (1982) showed something similar. People can be conditioned to treat fear-relevant stimuli as safety signals just as easily as fear-irrelevant ones.

Taken together, empirical support for preparedness theory is deeply ambivalent. Scholars have also questioned how Seligman (1971) interpreted phobias.

Many people report having feared stimuli such as snakes for as long as they can remember, rather than having acquired the fear through Pavlovian conditioning.

They rarely remember active harm from the stimulus, such as a snake bite. Instead, they report intense fear whenever they encounter it.

Researchers have also asked why some people develop fears and others do not.

Dog bites and falls from high places, for instance, occur about as often in the past of people without intense fears of dogs or heights. They occur just as often in the past of people who do have those fears (Di Nardo et al., 1988; Menzies & Parker, 2001).

Modern fears raise a further question. Does a fear of flying reflect a biologically prepared height phobia, or is it a product of contemporary society (McNally & Louro, 1992)?

Critical Evaluation

Jeffrey Gray (1987) raised a notable critique of preparedness and Öhman’s experiments, with three main points.

• Discrimination, not fear: the slower deconditioning to fear-related stimuli may simply reflect participants discriminating better between shocked and non-shocked fear-relevant cues, not a stronger conditioned fear.
• Orienting, not fear: participants in Öhman’s experiment may not have had a heightened fear response at all, only a stronger tendency to orient toward the fear-related pictures.
• Threat without shock: participants showed greater fear to fear-relevant stimuli even when merely threatened with a shock that never occurred (Öhman et al., 1974).
• Sensitization, not conditioning: this pattern suggests sensitization to fear cues rather than genuine Pavlovian conditioning, a reading Lovibond, Siddle, and Bond’s (1993) experiment later supported (McNally, 2016).

Gray argued that true prepared conditioning would produce larger responses overall to fear-related stimuli that actually provided shocks, not just a slower loss of the response.

The theory is not without its strengths. Its predictions were confirmed in advance: fear conditioning would be selective for evolutionary threats, and this was later supported by both human and animal studies. This cross-species reach is what separates preparedness from a purely after-the-fact description.

Preparedness also sits awkwardly with fears of modern, evolutionarily novel objects, such as aeroplanes, needles, or driving, which have no ancestral referent.

It risks circular reasoning, too. Unless survival relevance is defined independently of how easily a fear is learned, calling an association “prepared” simply relabels the ease of learning it was meant to explain.

Expectancy Theory, Nonassociative Theory, and Covariation Bias

Following Gray’s critique, scientists shifted focus from Pavlovian conditioning toward accounts consistent with his selective-sensitization view. Three rival approaches stood out.

• Expectancy theory: fear selectivity is shaped by learned, cultural expectations about danger.
• Nonassociative theory: some fears need no conditioning at all, only an evolutionary predisposition.
• Covariation bias: people overestimate how strongly fear-relevant stimuli predict bad outcomes.

Expectancy Theory

Expectancy theory, formulated by Davey (1992), holds that ontogenetic (cultural) factors shape expectations about which stimuli are likely to be linked to adverse events, such as shocks in the laboratory.

On this view, fear is not a fixed inheritance. It is shaped by what a culture teaches its members to expect as dangerous, layered on top of any evolutionary bias.

Consistent with biological preparedness, snakes and spiders incited larger fear responses than flowers did. Guns were the exception.

They only produced a higher fear response when the picture showed the gun pointed at the participant. Guns are common, lethal threats today, yet they did not automatically outrank ancestral dangers.

That is a real limit.

It suggests a purely cultural story cannot be the whole answer. Davey’s work argues that both evolution and social expectations shape how fear responses develop (McNally, 2016).

Nonassociative Theory

Nonassociative theory keeps the emphasis on evolution (Menzies & Clarke, 1995). It holds that people respond, particularly during childhood, with different amounts of fear to different stimuli.

The amount depends on the threat those stimuli posed across human history, such as snakes and heights (McNally, 2016).

These fears need no painful experience to form. That is what makes them nonassociative.

On this account, a fear can appear the first time a person ever meets the stimulus, already at full intensity, with no conditioning episode behind it at all.

This competes directly with preparedness itself. Both agree the fear is not equipotential, but they disagree about whether any learning episode is needed at all.

Menzies and other theorists treat nonassociation as one of four routes to fear. The others are Pavlovian conditioning, observational learning, and verbal transmission of threatening information (Rachman, 1977).

Covariation Bias

Covariation bias grew out of work by researchers such as Tomarken, Mineka, and Cook. They found that people were more likely to associate pictures of common fear stimuli with negative outcomes in the lab. The outcomes were identical.

Every picture type, fear-relevant or not, was in fact paired with the same shocks at the same rate throughout the experiment.

The bias is in the remembering, not the pairing. Fear-relevant images are recalled afterwards as more strongly linked to bad outcomes than they actually were.

This matters for the wider debate. It offers a purely cognitive account of an effect that looks selective, without needing any evolved mechanism behind it.

The effect has limits, too. A later study found it applied only to phylogenetic, evolutionarily backed, fear stimuli, not to ontogenetic, man-made ones (Tomarken, Sutton, & Mineka, 1995).

Examples

Taste Aversion in Humans

One of the most notable lines of research in biological preparedness is taste aversion. Biological preparedness argues that organisms are more likely to become averse to foods traditionally associated with sickness and gastrointestinal distress.

Besides Garcia and Koelling’s (1966) study on how sweetened water inspired taste aversion in rats paired with radiation-induced gastrointestinal distress, other researchers have studied the effect.

Bernstein and Webster (1980) examined learned taste aversion in humans. They exposed adults receiving chemotherapy to one of two novelty-flavored ice creams. Participants later favored the ice cream flavor they had received far less than the other flavor.

Bernstein had previously run a similar study on children receiving nausea-inducing treatment (1982). Bernstein and Webster explained both results along evolutionary lines.

Product Design and Marketing

Purucker, Sprott, and Herrmann (2014) elicited biological preparedness in a very different context: the design of car fronts.

Participants viewed pictures of car fronts designed to appear anthropomorphically threatening, such as those resembling an angry human face, and their responses were measured through eye-tracking.

The researchers found that these threatening designs both elicited self-reported affective responses and produced automatic responses “explained by evolutionary theory.”

This fits the so-called “threat advantage effect.” Threateningly designed cars initially drew participants’ attention but were ignored over time.

Instinctive Drift

If taste aversion is the great constraint on classical conditioning, instinctive drift is the equivalent constraint on operant conditioning.

The phenomenon was documented by Keller and Marian Breland, former students of B. F. Skinner who ran a commercial animal-training business.

The report’s strength is its breadth: thousands of animals across dozens of species, observed over long periods in applied settings rather than brief lab sessions.

Its weakness is that it is observational, not experimental. The training conditions were not controlled, so the interpretation, though compelling, rests on qualitative description rather than a manipulated variable.

References

Åhs, F., Rosén, J., Kastrati, G., Fredrikson, M., Agren, T., & Lundström, J. N. (2018). Biological preparedness and resistance to extinction of skin conductance responses conditioned to fear relevant animal pictures: A systematic review. Neuroscience & Biobehavioral Reviews, 95, 430-437.

Bernstein, I. L., & Webster, M. M. (1980). Learned taste aversions in humans. Physiology & Behavior, 25(3), 363-366.

Bernstein, I. L., Webster, M. M., & Bernstein, I. D. (1982). Food aversions in children receiving chemotherapy for cancer. Cancer, 50(12), 2961-2963.

Breland, K., & Breland, M. (1961). The misbehavior of organisms. American Psychologist, 16(11), 681-684.

Csikszentmihalyi, M., & Seligman, M. (2000). Positive psychology. American Psychologist, 55(1), 5-14.

Davey, G. C. (1992). Classical conditioning and the acquisition of human fears and phobias: A review and synthesis of the literature. Advances in Behaviour Research and Therapy, 14(1), 29-66.

Dawson, M. E., Schell, A. M., & Banis, H. T. (1986). Greater resistance to extinction of electrodermal responses conditioned to potentially phobic CSs: A noncognitive process? Psychophysiology, 23(5), 552-561.

Di Nardo, P. A., Guzy, L. T., Jenkins, J. A., Bak, R. M., Tomasi, S. F., & Copland, M. (1988). Etiology and maintenance of dog fears. Behaviour Research and Therapy, 26(3), 241-244.

Foa, E. B., & McNally, R. J. (1986). Sensitivity to feared stimuli in obsessive-compulsives: A dichotic listening analysis. Cognitive therapy and research, 10(4), 477-485.

Garcia, J., & Koelling, R. A. (1967). A comparison of aversions induced by X rays, toxins, and drugs in the rat. Radiation Research Supplement, 7, 439-450.

Gray, J. A. (1987). Perspectives on anxiety and impulsivity: A commentary.

Maturski, E. J., Bond, N. W., Siddle, D. A., & Lovibond, P. F. (1993). Classical Conditioning of Autonomic and Affective Responses to Fear‐Relevant and Fear‐Irrelevant Stimuli. Australian journal of psychology, 45(2), 69-73.

McNally, R. J. (2016). The legacy of Seligman’s” phobias and preparedness”(1971). Behavior therapy, 47(5), 585-594.

McNally, R. J., & Reiss, S. (1982). The preparedness theory of phobias and human safety-signal conditioning. Behaviour Research and Therapy, 20(2), 153-159.

Menzies, R. G., & Clarke, J. C. (1995). The etiology of phobias: A nonassociative account. Clinical Psychology Review, 15(1), 23-48.

Menzies, R. G., & Parker, L. (2001). The origins of height fear: an evaluation of neoconditioning explanations. Behaviour Research and Therapy, 39(2), 185-199.

Purucker, C., Sprott, D. E., & Herrmann, A. (2014). Consumer response to car fronts: eliciting biological preparedness with product design. Review of Managerial Science, 8(4), 523-540.

Rachman, S. (1977). The conditioning theory of fearacquisition: A critical examination. Behaviour Research and Therapy, 15(5), 375-387.

Seligman, M. E. P. (1970). On the generality of the laws of learning. Psychological Review, 77(5), 406-418.

Seligman, M. E. (1971). Phobias and preparedness. Behavior therapy, 2(3), 307-320.

Tomarken, A. J., Sutton, S. K., & Mineka, S. (1995). Fear-relevant illusory correlations: What types of associations promote judgmental bias? Journal of abnormal psychology, 104(2), 312.

Further Information

• Öhman, A., & Mineka, S. (2001). Fears, phobias, and preparedness: toward an evolved module of fear and fear learning. Psychological review, 108(3), 483.
• Poulton, R., & Menzies, R. G. (2002). Fears born and bred: toward a more inclusive theory of fear acquisition. Behaviour Research and Therapy, 40(2), 197-208.
• Öhman, A., Soares, S. C., Juth, P., Lindström, B., & Esteves, F. (2012). Evolutionary derived modulations of attention to two common fear stimuli: Serpents and hostile humans. Journal of Cognitive Psychology, 24(1), 17-32.
• Mineka, S., & Öhman, A. (2002). Born to fear: non-associative vs associative factors in the etiology of phobias. Behaviour research and therapy, 40(2), 173-184.
• Menzies, R. G., & Clarke, J. C. (1995). The etiology of phobias: A nonassociative account. Clinical Psychology Review, 15(1), 23-48.