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Behavioral endocrinology is the study of hormonal processes and neuroendocrine systems that influence or regulate behavior.[1][2] Analytical approaches include studies of natural variation among individuals[3][4] within populations of a single species, sex differences, differences among species,[5][6] and experimental manipulations of either the endocrine system or behavior itself.[7]


Sex Steroids and BehaviorEdit


Estrogens, together, make up a group of primary female sex hormones synthesized in the ovaries.

  • Sexual behavior
  • General behavior: In humans, estrogen has been found to play a role in behavioral inhibition and controlling dangerous or unwanted behaviors in both men and women.[9]


Testosterone is secreted by the testicles of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.[10]

There has been much debate and research devoted to the relationship between testoserone and aggression.[11]

Men produce approximately ten times more testosterone than women, so even low-testosterone men have more than any woman. Physically, it generates such male traits as body hair and pattern baldness. Psychologically, testosterone promotes:

    • a sense of separateness
    • aggression and risk-taking (sex drive (but not touch affection) and sexual fantasy)
    • anxiety or energy leading to poor concentration
    • assertiveness and self-confidence
    • visual-spatial ability and interest in moving things
    • violent, criminal, or psychotic behavior [12]

Several studies have established that testosterone therapy has reduced negative mood, depression, fatigue, and self-esteem.

Thyroid HormonesEdit

thyroxine (T4) and triiodothyronine (T3)Edit

thyroxine (T4) and triiodothyronine (T3) are the main hormones released in the thyroid gland. They are synthesized from tyrosine and iodine in the blood stream. These hormones travel via bloodstream to almost every cell throughout the body and function to regulate their target cell's metabolism. These hormones are a product of the hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis). These organs function together as the hypothalamus releases thyrotropin releasing hormone (TRH), which cause the pituitary gland to secrete thyrotropin that signal the thyroid gland to process and release thyroxine and triiodothyronine to the body. These hormones play a major role in the Neuroendocrine system which regulates the vital body functions of breathing, body weight, heart rate, muscle strength, cholesterol levels, especially body temperature. When your body has to much or too little of these hormones it has abnormal affect throughout your body:

The production of too much Thyroxine and triiodothyronine result in Hyperthyroidism. Some potential side effects are:

    • Anxiety
    • Irritability or moodiness
    • Hyperactivity and nervousness
    • Excessive sweating and sensitivity to higher temperatures
    • Hand Trembling
    • Missed or light menstrual periods

The production of too little thyroxine and triodothyronine results in Hypothyrodism. Some potential side effects are:

    • Trouble sleeping
    • Fatigue
    • Dry skin or hair
    • Concentration difficulties
    • depression
    • Sensitivity to cold temperatures
    • Frequent and heavy menstrual periods
    • Joint and muscle pain

Adrenal HormonesEdit

The 2 adrenal glands are located on the top of the kidney and have two distinct sections. The outer region called the outer part which is called the adrenal cortex. The adrenal cortex produce the hormones that are essential for life such as Cortisol and Aldosterone. The inner section, or the Adrenal medulla produce hormones that are not essential for life itself but assist the body in its functions, and these would include a hormone such as Adrenaline.


Cortisol is produced by the adrenal cortex above the kidneys and plays a major factor in neuroendocrinological behaviors. Cortisol helps in the regulation of metabolism and helps the body and brain respond to stress. Higher levels of cortisol to stressful situations promote:

  • Mental and physical preparation for stress
    • weakened inflammatory actions resulting in temporary pain toleration
    • fat, carbohydrate, and protein metabolism resulting high blood glucose levels (glucogenesis)
    • Sleep deprivation
    • Temporarily impaired cognitive performance
    • Possible anxiousness


Adrenaline, or other wise known as Epineephrine) is released from the Adrenal medulla. Adrenaline is also released in response to the stimulation of the sympathetic nervous system or stress. Adrenal is known as the "fight or flight" hormone as rapidly rushes blood to muscles and brain and produce the effects:

    • Increase overall muscular function
    • Increase awareness
    • increased excitability
    • increased desire and emotion

See alsoEdit


  1. ^ Becker, J. B., and S. M. Breedlove. 2002. Introduction to behavioral endocrinology. Pp. 3–38 in Behavioral endocrinology. MIT University Press.
  2. ^ "Society for Behavioral Neuroendocrinology." Society for Behavioral Neuroendocrinology. N.p., n.d. Web. 05 Mar. 2014.
  3. ^ Tryon, R. C. 1942. Individual differences. Pages 330-365 in F. A. Moss, ed. Comparative psychology. Prentice-Hall, New York.
  4. ^ Careau, V., and T. Garland, Jr. 2012. Performance, personality, and energetics: correlation, causation, and mechanism. Physiological and Biochemical Zoology 85:543–571.
  5. ^ Abbott, D. H., E. B. Keverne, F. B. Bercovitch, C. A. Shively, S. P. Mendoza, W. Saltzman, C. T. Snowdon, T. E. Ziegler, M. Banjevic, T. Garland, Jr., and R. M. Sapolsky. 2003. Are subordinates always stressed? a comparative analysis of rank differences in cortisol levels among primates. Hormones and Behavior 43:67–82.
  6. ^ Goymann, W., I. T. Moore, A. Scheuerlein, K. Hirschenhauser, A. Grafen, and J. C. Wingfield. 2004. Testosterone in tropical birds: effects of environmental and social factors. The American Naturalist 164:327–334.
  7. ^ "Introduction_to_Behavioral_Endocrinology".
  8. ^ Nelson, Randy Joe. An Introduction to Behavioral Endocrinology. Sunderland, MA: Sinauer Associates, 2005. Print.
  9. ^ "Research on Estrogen and Behavior is a 'Hot Topic' at the 2011 Society for Neuroscience Meeting".
  10. ^ Tuck SP, Francis RM (2009). "Testosterone, bone and osteoporosis". Front Horm Res. Frontiers of Hormone Research 37: 123–32. doi:10.1159/000176049
  11. ^ “Effects of Testosterone on Mood, Aggression, and Sexual Behavior in Young Men: A Double-Blind, Placebo-Controlled, Cross-Over Study.” 2004. The Journal of Clinical Endocrinology & Metabolism 89(6): 2837–45. (July 13, 2014).
  12. ^ Bulletin of Psychological Type, Volume 26, No 4, 2003

External linksEdit