Magic Mustang Tamer

 The Neural Basis of Optimism and Pessimism

In this review article, Hecht provides evidence that appraisal of future events is tied to the lateralization of the brain, with the left hemisphere (and right sensory organs) tuned to predict positive outcomes, and more negative ones in the right hemisphere.

Journal Reference: Hecht, D. (2013). The neural basis of optimism and pessimism. Experimental neurobiology, 22(3), 173.

Publication Date: September 2013


David Hecht reviewed the neuroscience literature on optimism and pessimism. He found that while conscious experience is a synthesis of the activity of both hemispheres, that the valence of appraisal was mediated differentially by the two hemispheres. In addition to providing a reference for understanding the emotional responses to brain damage, this research suggests that the balance of emotional response to future prospects can be managed with conscious control of lateralized stimulation.


If you want to inspire confidence about the future in your partner, which ear do you whisper in? David Hecht says that contra-lateral stimulation can activate the left or right hemisphere of the brain, impacting anticipation of future events and that an optimistic view, even if it is not totally realistic, will lead to better outcomes in the long run. Whispering in the right ear will activate the left hemisphere, leading the listener to discount negative information and persist through challenges.

While Hecht’s review and synthesis is focused on people, we know that laterality is an important aspect of equine psychology. We also know that horses can trust or distrust us, interpreting every event in the training environment skeptically or expectantly. The appraisal of events in process is analogous to being optimistic and pessimistic. If we could learn to promote optimism in our animals, even by just a small percentage, our jobs would be easier.

“Together, these studies demonstrate the existence of a fundamental difference between the two hemispheres: the LH mediates a brighter outlook on the world and ignores negative aspects in one’s environment, while the RH mediates a tendency to concentrate on the glass half empty, which leads to the anticipation of a dismal future.”

Hecht, 2013

The cognitive mechanisms known to affect human appraisal of the future include 1) selective attention, 2) belief in the ability to control any aspect of the future, and 3) personal attribution style. While these may not be as evident in the equine mind, there is little reason to think they are not factors in the appraisal of events for horses. Horses show selective attention by ignoring the dog, while they nicker at our approach. The pessimism of learned helplessness is something no trainer wants, while the unbridled optimism of an empowered but undisciplined colt is something no trainer ignores for long, striving to retain optimism while inculcating discipline. Finally, if you doubt that horses have personal attribution styles, consider the temperament of the emotional pony in contrast to the placid draft horse.

Appraisal of Future Optimistic Pessimistic
Brain Hemisphere Left Hemisphere Right Hemisphere
Contra-lateral sensory input Right side Left side
Coping Strategy Proactive Passive
Persistence Escape & Avoidance
Autonomic Nervous System  PSNS SNS

One facet of this paper Hecht discussed the effect of a stroke on the RH might produce activation of the LH leading to a sense of optimism that might interfere with the realization of the need for medical attention. Synchronistically, within a few days of learning this, I heard someone discussing their own experience of an RH stroke as an experience of great curiosity and blissfulness. They delayed getting medical treatment which made the recovery process take much longer. It seems out of place to discuss this here, but perhaps a reader will need to know this can happen.

Among the 320 references cited in this article, I found one of particular interest. Wilkerson et al, 2010 performed a spatial bias test after empowering or disempowering the test subjects to preferentially activate different hemispheres of the brain. They found that disempowered subjects, which would have more activated right hemispheres and more deactivated left, were less likely to attend to and avoid obstacles in their right visual field. This matched other studies that had previously established that hemisphere deactivation was associated with contra-lateral spatial neglect.

For horse training, we know that most wild or fearful horses prefer to keep people on their left sides and that some especially fearful horses prefer to keep people on their right sides. If we could apply the findings of this article to horses, we might hypothesize that in the left visual field, we would be stimulating the right hemisphere, engendering some pessimistic appraisal of the situation. We might have better luck with positive respondent conditioning on the right side. 

We might also hypothesize that we could sort optimistic and pessimistic horses by exploiting their spatial neglect. This is a testable hypothesis. 

  • Keywords: laterality, optimism, pessimism, spatial neglect, empowerment

Other papers mentioned: Wilkinson, David, Ana Guinote, Mario Weick, Rosanna Molinari, and Kylee Graham. “Feeling socially powerless makes you more prone to bumping into things on the right and induces leftward line bisection error.” Psychonomic Bulletin & Review 17 (2010): 910-914.

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