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If You Feel Alone and Afraid, Warm Up Your Hands

A recent study suggests physical warmth inhibits fear learning and response.

Key points

  • Social support often reduces fear, perhaps because social support is a “prepared safety stimulus,” meaning it helped our ancestors survive.
  • Just like social support, physical warmth tends to reduce fear learning and responding and thus appears to be a prepared safety stimulus.
  • Physical warmth may be used to improve current treatments for anxiety disorders and post-traumatic stress disorder (PTSD).
Source: nastya_gepp/Pixabay

Have you ever wondered why it is easier to learn to fear spiders and snakes than motorcycles or guns?

According to the “biological preparedness” theory, human beings’ evolutionary past holds the answer: Since venomous spiders and snakes posed a major threat in ancestral environments, human beings who quickly learned to avoid these dangerous animals were more likely to survive and reproduce.

Therefore, behaviors like fear of snakes or spiders are easier to learn than the fear of, say, guns, electrical outlets, or vehicles.

What might reduce fear learning and fear response is the presence of prepared safety stimuli, such as parents, friends, or anybody else who provides emotional and social support (i.e., security, resources, comfort).

Again, the evolutionary explanation is that our ancestors were more likely to survive and reproduce successfully if they received care, kindness, and help from social support providers.

Perhaps physical warmth could be considered another prepared safety stimulus, suggest Hornstein et al., in their recent paper, published in Emotion. Why? Because not only is physical warmth necessary for survival, but it is also associated with interpersonal warmth—meaning the qualities of being generous, caring, and kind, which many support providers possess.

Hornstein and colleagues’ investigation of physical warmth as a potential safety stimulus is described below.

Investigating physical warmth as a safety stimulus

Study 1

The goal was to investigate fear learning for different types of objects (e.g., soft, warm).

Sample: 31 individuals (21 females); average age of 21; 42 percent white.

Methods: After determining the appropriate level of shock for all participants (so the shock is experienced as “extremely uncomfortable,” but not painful), the fear conditioning session began.

The conditional stimuli—a warm pack, a wooden block, a rubber ball, and a fuzzy ball—were placed, one by one, in a participant’s right hand for six seconds. During the first step (i.e., habituation), this was repeated several times, which allowed researchers to determine the baseline arousal.

In the second stage (acquisition), all objects were again presented multiple times. However, participants were given a 200-ms shock after they had received the rubber ball, fuzzy ball, or warm pack—except the wooden block, the control object.

At this point, participants watched a five-minute clip about airplanes. (Note, airplanes were the subject of all videos mentioned below.)

During the third phase (i.e., extinction), the objects were presented again, though without the shock.

Study 2

The aim was to determine if holding a warm pack would prevent fear responding.

Sample: 30 individuals (22 females); average age of 21; 47 percent Caucasian.

Methods: After shock calibration (as described previously), participants underwent a fear conditioning session. They were presented with the following conditional stimuli: pictures of a clock, a cup, and a stool.

In the acquisition step, which occurred after the habituation stage and evaluation of baseline arousal, stimuli’s photos were shown several times. Images of the clock and stool were always—and the cup was never—paired with an electric shock.

Then followed a three-minute video.

Later, during the summation stage, whenever pictures of the clock and stool were shown to a participant, one of two objects (warm pack, rubber ball) was placed in his or her hand for 10 seconds. The cup’s image was paired with the wooden block.

Then followed another three-minute video.

In the test phase, participants were repeatedly shown each of the conditional stimuli alone.

Physical warmth can reduce anxiety

Analysis of data showed, “physical warmth resists becoming associated with a fear response (Study 1) and inhibits the fear response (Study 2), demonstrating that physical warmth passes both the retardation-of-acquisition and summation tests without any prior safety training.”

In other words, physical warmth has the same lasting effect as the presence of a social support provider and can be considered a prepared safety stimulus.

This makes sense because both appear to share the same neurobiological pathways, pathways that have “evolved to ensure access to physical warmth and social connections by motivating organisms to seek out such experiences and reinforcing them when they occur.”

For instance, “opioid processes have been shown to play an important role in regulating physical warmth,” “maintaining social bonds,” “and supporting warmth-induced feelings of social connection.” The opioid system is also involved in fear conditioning.

Source: Up-Free/Pixabay

Physical warmth and treatments for anxiety disorders and PTSD

The research reviewed found physical warmth is a type of prepared safety stimulus, and thus facilitates long-term fear reduction.

This is not surprising because, for one, warmth is essential for survival. To illustrate, newborns (particularly preterm infants) who are kept warm are more likely to survive. And second, physical warmth is often associated with interpersonal warmth and social support.

These findings, which support the use of physical warmth as a safety stimulus, have important implications for helping patients with anxiety disorders and post-traumatic stress disorder (PTSD)—conditions associated with deficits in safety learning or failure to inhibit fear responses in the presence of safety cues.

For instance, a limitation of many treatments, such as exposure therapy—which involves confronting feared or avoided stimuli—is the relatively high relapse rate. In other words, fear and anxiety often return after initial improvement.

Since prepared safety stimuli have a lasting inhibitory effect, they may overcome these limitations of exposure therapy and other psychological treatments for anxiety disorders and PTSD.

Of course, pleasant sensations of warmth can also make the treatment and exposure to feared objects and situations less aversive.