Look Again

“Habituation” causes humans to grow apathetic to both pleasure and misery.

A study sponsored by a tourism company found that holidaymakers are happiest 43 hours into their vacations. Thereafter, the sheen of the trip starts to fade. Why? By 43 hours, vacationers have settled into their lodgings and enjoyed a string of firsts: their first glimpse of the ocean, their first taste of local cuisine, and so on. Then habituation sets in. Second experiences are rarely as enjoyable as firsts. 

Habituation is defined as a “diminishing physiological or emotional response to a frequently repeated (or constant) stimulus,” and it is responsible for humans’ desensitization to both the good and bad aspects of life. Consider your disgust upon entering a room filled with cigarette smoke, and how, 20 minutes later, you can hardly detect the smell. The neurons in your brain react strongly to new stimuli, but unless you leave or change the environment, inhibitory neurons will fire to quell your brain’s initial response.

Habituation is necessary for survival. Once you have established that something ...