As skeptical researchers with a penchant for thorough and accurate assessments of the strengths and weaknesses of positive thinking and optimism, we are dismayed by Salerno's apparent lack of comprehension (and exclusion of references to back up his claims) when it comes to the hundreds of studies relating to this important psychological and neurological topic. A brief analysis of the 97 abstracts that are cited if you enter "positive thinking" (let alone the 3553 references to its companion term, optimism) as a key word in the databases of the National Library of Medicine and the National Institutes of Health (www.pubmed.gov) will demonstrate that Salemo has not done his homework.
Hope, optimism, and the belief in a positive future (i.e., faith) are essential for human psychological and neurological functioning, a concept that was first addressed in the 1950s by the psychiatrist Vicktor Frankl, who was imprisoned in a Nazi death camp until the end of World War II. In his famous book, Man's Search for Meaning, he said that the single most important thing that kept a survivor alive was faith. If a prisoner lost faith in the future, he was doomed, because the will to live seldom returned. For Frankl, faith was essential for dealing with all aspects of life: "A weak faith is weakened by predicament and catastrophes whereas a strong faith is strengthened by them." (1)
Now, faith in an optimistic future may be a placebo, but it's important to remember that placebos can cure, on the average, 30% of the majority of physical and emotional diseases. Even an irrational belief in a cure that has been proven not to work can significantly boost the body's immune system when dealing with a deadly disease.2
But what about unrealistic faith or optimism? Recently, a team of National Institutes of Health researchers concluded that "a moderate optimistic illusion" appears to be neurologically essential for maintaining motivation and good mental health. (3) They also found that highly optimistic people had greater activation in the same parts of the anterior cingulate, a part of the brain that plays a crucial role in controlling anxiety, depression, and rage, as well as fostering social awareness and compassion. (4)
Even the medical researchers at the Mayo Clinic stress the importance of optimistic thinking for maintaining optimal health. They found that positive thinking decreases stress, helps you resist catching the common cold, reduces your risk of coronary artery disease, eases breathing if you have certain respiratory diseases, and improves your coping skills during hardships. (5) An optimistic attitude specifically reduces the stress-eliciting cortisol levels in your body. (6) Many other studies have demonstrated how optimism improves behavioral coping in a variety of physical illnesses. (7) In a forty year follow-up conducted at Duke University, optimists had increased longevity when compared to pessimistic individuals. (8)
As reported in the November 2007 issue of Nature, if the human brain did not have a bias toward optimism, we would be prone to increased anxiety and depression. (9) However, anxious individuals have a more difficult time suppressing negative thoughts, (10) and often get caught up in the repetitive process of rumination. This, unfortunately, strengthens the neural circuits that are generating anxiety and embedding the information into long- term memory banks.
Optimism is also related to the neurological mechanism known as the placebo effect. If you strongly believe in something--in other words, if you have enough faith in yourself--you will stimulate both your immune system and your motivational system into action. (11)
Skeptics might argue that maintaining an illusory optimism is problematic, but the evidence points in the opposite direction. Researchers at the University of California found that people who have self-enhancing illusions exhibit …