Fear of falling

Gibson and Walk found that when placed on the board, 27 of the infants would crawl on the shallow side when called by their mothers; only three ventured off the "edge" of the cliff.

[2] Psychiatrists Isaac Marks and Randolph M. Nesse and evolutionary biologist George C. Williams have noted that people with systematically deficient responses to various adaptive phobias (e.g. basophobia, ophidiophobia, arachnophobia) are more temperamentally careless and more likely to receive unintentional injuries that are potentially fatal and have proposed that such deficient phobia should be classified as "hypophobia" due to its selfish genetic consequences.

[7] This syndrome was first mentioned in 1982 by Murphy and Isaacs,[8] who noticed that after a fall, ambulatory persons developed intense fear and walking disorders.

[11][12] Other risk factors of fear of falling in the elderly include dizziness, self-rated health status, depression, and problems with gait and balance.

It suggested that depth perception develops quickly in chickens, as the chicks never made the "mistake" of walking off the "deep" side of the cliff.

The postural control system has two functions: to ensure that balance is maintained by bracing the body against gravity, and to fix the orientation and position of the features that serve as a frame of reference for perception and action with respect to the external world.

Studies have shown that people afraid of heights or falling have poor postural control, especially in the absence of strong visual cues.

[16] When faced with high or unstable ground, the vestibular system in these individuals senses the instability and attempts to correct it by increasing postural sway to reactivate visual balance feedback (postural sway refers to the phenomenon of constant displacement and correction of the position of the center of gravity within the base of support).

Studies have shown that people with acrophobia and/or an extreme fear of falling have higher scores of SMD, or space and motion discomfort.

Space and motion discomfort arises when conflicting information is detected among visual, kinesthetic, and vestibular sensory channels.

[19] The results confirmed that typical dreams are consistent over time, region, and gender, and a few themes can be considered almost universal: falling (73.8% prevalence), flying or soaring in the air (48.3%) and swimming (34.3%).

They quote another author, Gutheil (1951), who suggests a range of possible meanings subsumed under the general idea of loss of (mental) equilibrium.