Randy Ludwig

1. Randy Ludwig The Biology of Love, Sex & Attraction TNDY 402 FEB 14— 2011

2. OVERVIEW: • Types of LOVE • Biochemistry of LOVE • Applications • Conclusion

3. A few Stats: Age of first marriage: Women: 24.8 years Men: 27.3 years The probability of first marriage by age 30: 74% for women 61% for men. The probability of first marriage by age 40: 86% for women 81% for men. (Goodwin, McGill, & Chandra, 2009)

4. A few Stats: 17% of women & 25% of men have not married by age 35. 12% of women have not married by age 40, 17% of men have not married by age 40. The probability that men and women will marry by age 40 is over 80%. (Goodwin, McGill, & Chandra, 2009)

5. TYPES: If it feels different, it is different • Lust (Sex) • Passionate Love (Infatuation/Romantic Love) • Companionate Love (Attachment) • Maternal Love

6. TYPES: Lust/Sex: • Non-selective sex, goodness of fit not important Main Drivers: • Testosterone: (C19 H28 O2 ) • Increases sexual arousal in men & women • Estradiol: (C18 H24 O2) • Associated with higher sexual activity in women • Higher masturbation rates • Preference for “manly” faces • Dopamine & Norepinephrine • Motivates sex “with any appropriate member of the species” • (Fisher et al, 2002, p. 414) • Increases here, don’t automatically increase other types of love Key Brain Areas Involved: • Medial insula • Anterior cingulate • Hypothalamus • Nucleus accumbens • VTA

7. TYPES: • Consists of “intense longing” and “physiological arousal” • (Aronson, Wilson, & Akert, 2010, p. 301) • Exhilaration and euphoria Passionate Love: • Exhilaration and euphoria Increases in: • Dopamine: (DA) • Norepinephrine: (NE) • Nerve Growth Factor (NGF) Phenylethylamine: PEA is a neurotransmitter released by a region of the brain called the hypothalamus. Theresa Crenshaw, M.D., author of The Alchemy of Love and Lust, (Pocket Books; 1997) calls PEA "the molecule of love". It plays a part in the "falling in love" stage accompanied by feelings of euphoria Decreases in: Key Brain Areas Involved: • Serotonin: (5HT) • Frontal Lobe • Amygdala • Parietal lobe • Anterior cingulate • Hippocampus • Nucleus accumbens • Hypothalamus • VTA • Caudate nucleus Excess DA & NE tend to reduce 5HT Obsession

9. Pleasure Centers In the Brain: 1. Sensory Cortex sends signal to VTA (ventral tegmental area) indicating pleasurable activity has occurred which increases VTA activity • The VTA releases dopamine which • travels to the nucleus accumbens Orbitofrontal Cortex (OFC) • High amounts of dopamine are then released • in the nucleus accumbens—equating to feelings • of desire, importance, and pleasure • Dopamine travels to prefrontal cortex where • it is also registered as pleasurable

10. Cingulate Gyrus 2. ________ Thalamus 3. ________ Corpus Callosum 1. ________ Nucleus Accumbens 11. ________ Cerebellum 4. ________ Hypothalamus 10. ________ Pituitary Gland 9. ________ Amygdala Hippocampus 5. ________ 8. ________ Medulla 6. ________ Pons 7. ________

11. TYPES: Arginine vasopressin (AVP) Companionate Love: • Calmer type of love, emotional bond • EX: grandparents married for 30 years Increases in: • Oxytocin: (OXT) • Vasopressin: (AVP) • Chemically similar • Produced in hypothalamus • Released from pituitary gland Decreases in: • Serotonin: (5HT)

12. TYPES: Arginine vasopressin (AVP) Maternal Love: • Parent & child Increases in: • Oxytocin: (OXT) • Vasopressin: (AVP) Brain implications: • Hypothalamus not activated • Striatum is activated • Slight reduction in frontal lobe Decreases in: • Serotonin: (5HT)

13. APPLICATIONS: Arginine vasopressin (AVP) Prairie Voles: • Socially monogamous (mate with others at times) • High levels of OXT & AVP receptors • If OXT & AVP blocked: they become promiscuous Montane Voles: • Promiscuous • No long-term attachment • OXT & AVP injections in montane voles doesn’t lead to monogamy—why?

14. Clark & Hatfield (1989): • Students were approached by another student of the opposite sex, who said: • “I have been noticing you around campus and I find you very attractive.” • This was followed by one of three invitations: • “Would you go out with me tonight?” • “Would you come over to my apartment?” • “Would you go to bed with me?”

15. 100 80 60 Percent Saying “Yes” About half of both sexes said “yes” to the date 40 20 0 Go Out Go to Apt. Go to Bed

16. 100 80 60 Percent Saying “Yes” About half of both sexes said “yes” to the date 40 20 0 Go Out Go to Apt. Go to Bed

17. 100 80 60 Not a single woman said “yes” to the sexual invitation Percent Saying “Yes” About half of both sexes said “yes” to the date 40 20 0 Go Out Go to Apt. Go to Bed

18. 100 80 60 Not a single woman said “yes” to the sexual invitation Percent Saying “Yes” About half of both sexes said “yes” to the date 40 20 0 Go Out Go to Apt. Go to Bed

19. Men were even more likely to say “yes” to the sexual invitation If men said “No,” then they typically apologized and/or offered an excuse such as “I’m dating someone” 100 80 60 Not a single woman said “yes” to the sexual invitation Percent Saying “Yes” About half of both sexes said “yes” to the date 40 20 0 Go Out Go to Apt. Go to Bed

20. Mate Preferences of Women • Economic Resources • Good Financial Prospects • High Social Status • Older Men • Ambition and Industriousness • Dependability and Stability • Athletic Prowess • Good Health and Physical Appearance • Love and Commitment • Willingness to Invest in Children

21. Mate Preferences of Males • Desire women who are: • Intelligent, kind, humorous, understanding, & healthy • Similar in terms of values, personality, and religious beliefs

22. In Addition... • Youth • A cue for fertility

23. Mate Preferences of Males • Youth • Physical Beauty • full lips, clear skin, smooth skin, clear eyes, lustrous hair, good muscle tone, & attractive body fat distribution • Behavior: youthful gait, animated facial expression, & high energy level • “Average” & symmetrical faces are more attractive

24. Mate Preferences of Males • In the US, women typically believe that men want women who are SLIMMER THAN AVERAGE…but men actually prefer women who are AVERAGE • Although men’s preferences for body size varies to some degree across cultures, one body shape preference is universal: a particular ratio between the size of a woman’s waist and the size of her hips • Youth • Physical Beauty • Body Fat and the Critical Waist-to-Hip Ratio (WHR) • Universal preference across cultures... • .70 is optimal

26. References: Arginine vasopressin (AVP) Clark, R.D., & Hatfield, E. (1989). Gender differences in receptivity oto sexual offers. Journal of Applied Social Psychology, 20, 771-782. Fisher, J, Aron, A, & Brown, L.L. (2005). Romantic Love: an fmri study of a neural mechanism for mate choice. The Journal of Comparative Neurology. 493:58, 58-62. Fisher, H.E., Aron, A., Mashek, D., Haifang, L., & Brown, L.L. (2002). Defining the brain systems of lust, romantic attraction, and attachment. Archives of Sexual Behavior. 31:5, 413-419. Johnson, S. (2009). Addicted to love. The Brain. Winter, 50-55. Savulescu, J., & Sandberg, A. (2008). Neuroenhancement of love and marriage: The chemicals between us. Nueroethics. !:31, 31-44 Zeki, S. (2006). The neurobiology of love. FEBS Letters 581, 2575-2579.