Why We Love (34 page)

24
. Ibid., p. 21.

25
. Ibid., p. i.

26
. Hamill 1996, p. 44.

27
.
Random House Treasury,
p. 362.

28
. Hatfield and Rapson 1996; Tennov 1979; Beach and Tesser 1988.

29
. Plato 1999, p. 40.

30
. Hamill 1996, p. 38.

31
. Whittier 1988, p. 46.

32
. Solomon 1990.

33
. Hopkins 1994, p. 42.

34
. Tennov 1979, p. 31.

35
.·Fowler 1994.

36
. Hopkins 1994, p. 22.

37
.·Hamill 1996, p. 59.

38
. Milton 1949.

39
. Tesser and Reardon 1981.

40
. Rocamora 1998, p. 84, 87, 94.

41
. Shakespeare 1936,
Romeo and Juliet,
act I, scene iv, lines 41–50.

42
. Ibid., act I, scene v.

43
. Whittier 1988, p. 30.

44
. Wolkstein 1991.

45
. Ibid., p. 129.

46
. Ibid., p. 101.

47
. Ibid., p. 48.

48
. Harris 1995, p. 110.

49
. Hopkins 1994, p. 87.

50
. Buss 1994; Buunk and Hupka 1987.

51
. Collins and Gregor 1995.

52
. Cancian 1987.

53
.·Yutang 1954, p. 73.

54
. Hopkins 1994, p. 18.

55
. Tennov 1979.

56
. Flexnor 1965.

57
. Plato 1999, p. 40.

58
. Marazziti et al. 1999.

59
. Tesser and Reardon 1981.

60
.
Random House Treasury,
p. 321.

61
. Hatfield and Walster 1978.

62
. Darwin 1872/1965.

2. Animal Magnetism: Love among the Animals

1
. Darwin 1871/n.d., p. 745.

2
. Ibid., p. 744.

3
. Moss 1988, p. 118.

4
. Ryden 1989, p. 147.

5
. King 1990, p. 127.

6
. Penny 1988, p. 28.

7
. Harrington and Paquet 1982, p. v.

8
. Mech 1970, p. 112.

9
. Darwin 1871/n.d., p. 674.

10
. Smuts 1985, pp. 4–5.

11
. Tinbergen 1959, p. 29.

12
. Dagg and Foster 1976, p. 129.

13
. Schaller 1973, p. 78.

14
. Moss 1988, p. 115.

15
. Galdikas 1995, pp. 144–45.

16
. Schaller 1973, p. 79.

17
. Sankhala 1977, p. 67.

18
. Churchfield 1991, p. 27.

19
. Darwin 1871/n.d., p. 653.

20
. Ryden 1989, p. 51.

21
. Thomas 1993, pp. 54–55.

22
. Thomas 1993, p. 72.

23
. Hill and Smith 1984.

24
. Goodall 1986, p. 446.

25
. Ibid.

26
. Beach 1976, p. 131.

27
. Darwin 1871/n.d., p. 704.

28
. Wilson and Daly 1992.

29
. Goodall 1986, p. 446.

30
. Thomas 1993, p. 46.

31
. Pines 1999; Kanin et al. 1970.

32
. Brodie 1998, p. 257.

33
. Rebhun 1995, p. 245.

34
. Harris 1995, p. 122.

35
. McNamee 1984, p. 19.

36
. Barash and Lipton 2001.

37
.·Thomas 1993, p. 49.

38
. Goodall 1986, p. 459.

39
. Wilson and Daly 1992.

40
. Schmitt and Buss 2001.

41
. Schmitt 2001.

42
. Melis and Argiolas 1995; Dluzen et al. 1981; Herbert 1996; Etgen et al. 1999; Etgen and Morales 2002.

43
. Herbert 1996.

44
. Gingrich et al. 2000; Young et al. 1998.

45
. Insel and Carter 1995.

46
. Wang et al. 1999; Gingrich et al. 2000.

47
. Gingrich et al. 2000.

48
. Dluzen et al. 1981.

49
. Fabre-Nys et al. 1997.

50
. Etgen et al. 1999.

51
. Wolkstein 1991, p. 79.

52
. Some scientists believe animals lack evolved regions of the cerebral cortex and other brain systems that produce consciousness and self-consciousness, the mechanisms that are necessary to be consciously
aware
of one’s emotions. Others believe higher mammals do perceive their emotions (Humphrey 2002; De Waal 1996). I suspect conscious awareness of one’s self, one’s feelings, and the external world varies from a simple awareness of “here” and “now” to an extended conscious awareness of the distant past and future (Damasio 1994). Mammals are distributed along this continuum: many are aware of their emotions, including their attraction to specific others. But they do not think about these feelings with detailed self-analysis.

3. Chemistry of Love: Scanning the Brain “in Love”

1
. Homer 1990, p. 376.

2
. Horvitz et al. 1997; Schultz et al. 1997; Schultz 2000.

3
. Kiyatkin 1995; Salamone 1996; Robbins and Everitt 1996; Wise 1996; Luciana et al. 1998.

4
. Murray and Holmes 1997.

5
. Horvitz et al. 1997; Schultz et al. 1997; Schultz 2000.

6
. Pfaff 1999; Panksepp 1998.

7
. Wise 1988; Colle and Wise 1988; Post, Weiss, and Pert 1988; Kruk and Pycock 1991; Volkow et al. 1997.

8
. Abbott 2002; Schultz et al. 1997; Wise 1989, 1996, 1988; Robbins and Everitt 1996.

9
. Schultz 2000; Martin-Soelch et al. 2001.

10
. Griffin and Taylor 1995.

11
. Flament et al. 1985; Hollander et al. 1988; Thoren et al. 1980.

12
. H. Fisher 1998.

13
. Marazziti et al. 1999.

14
. Luciana, Collins, and Depue 1998.

15
. Whittier 1988.

16
. Mashek, Aron, and Fisher 2000.

17
. Hatfield and Sprecher 1986a; Berscheid and Reis 1998; Walster et al. 1966.

18
. Whittier 1998, “The Sun Rising,” p. 25.

19
. Aron, Aron, and Allen 1998.

20
. Hatfield and Sprecher 1986a.

21
. Plato 1999, p. 23.

22
. Ibid., p. 24.

23
. Flexnor 1965, p. 200.

24
. H. Fisher et al. 2003; Aron et al. (in preparation).

25
. The brain has two halves or hemispheres. Hence you have two caudate nuclei, one in your right brain and one in your left brain. In our experiment, we found activity only in the right caudate tail and body, as well as in the right ventral tegmental area. Many neuroscientists currently believe that the positive emotions emanate largely from
left
brain structures while negative emotions arise mainly from
right
brain structures. But several experiments contradict this generality, reporting positive emotions that arise from right brain regions. We don’t know why our love-sick individuals showed activity in the right caudate and VTA, rather than in the left caudate or bilaterally. My guess is that early stage romantic love is associated with underlying feelings of anxiety and craving, uncomfortable states of mind.

26
. Schultz 2000; Delgado et al. 2000; Elliott et al. 2003; Gold 2003.

27
. Saint-Cyr 2003; Knowlton et al. 1996.

28
. Small et al. 2001.

29
. Wise 1996; Volkow et al. 1997; Schultz, Dayan, and Montague 1997; Schultz 2000; Fiorillo, Tobler, and Schultz 2003; Martin-Soelch et al. 2001; Breiter et al. 2001.

30
. H. Fisher 1998; H. Fisher et al. 2002a; H. Fisher et al. 2002b.

31
. Schultz 2000.

32
. Horvitz et al. 1997; Wickelgren 1997.

33
. Damasio 1994.

34
. Bartels and Zeki 2000.

35
. Damasio 1994.

36
. Bartels and Zeki 2000; Gehring and Willoughby 2002; Luu and Posner 2003; Richmond et al. 2003.

37
. Brown, personal communication.

38
. Aron and Aron 1991; Aron et al. 1995; Aron and Aron 1996.

39
. Neuroscientist Donald Pfaff maintains (Pfaff 1999) that all drives have two components: (a) A
generalized
arousal system in the brain produces the energy and motivation to acquire all biological needs. (b) A
specific
constellation of brain systems produces the feelings, thoughts, and behaviors associated with each particular biological need. He reports that the general arousal component of
all
drives is associated with the action of dopamine, norepinephrine, serotonin, acetylcholine, the histamines, orexin, prostaglandin D synthase, and perhaps other brain chemicals. The specific constellation of brain regions and systems associated with
each
particular drive varies considerably. Our fMRI study appears to have uncovered the general arousal component of romantic love, associated with the ventral tegmental area and the distribution of central dopamine. However, we also found activation in the caudate body and tail, the septum, white matter of the posterior cingulate, and other areas, as well as deactivations in several brain regions (H. Fisher et al. 2003; Aron et al., in preparation). These may constitute part of the system specific to intense, early stage romantic love. A different protocol and/or more sophisticated technology will probably be necessary to establish the full set of neural correlates associated with the drive to love. However, the feelings, thoughts, motivations, and behaviors associated with romantic passion may be so varied across individuals, as well as so varied across time within each individual, that the full set of basic systems involved is impossible to record by group analysis.

40
. Pfaff 1999.

41
. Plato 1999, p. 40.

42
. The caudate nucleus has many receptor sites for both norepinephrine and serotonin (Afifi and Bergman 1998). But further research is necessary to establish whether these and/or other regions become active as one feels romantic passion.

43
. Several regions of the prefrontal cortex are associated with monitoring rewards. The orbitofrontal cortex is specifically involved in detecting, perceiving, and expecting rewards (Schultz 2000), as well as discriminating between rewards and making preferences (Schultz 2000; Martin-Soelch et al. 2001; Rolls 2000). With the nearby medial prefrontal cortex, we experience our emotions, bestow meaning to our perceptions (Carter 1998; Teasdale et al. 1999), guide our reward-related behaviors (Öngür and Price 2000), create our mood (Öngür and Price 2000, p. 216), and also make preferences (Öngür and Price 2000, p. 215). The caudate nucleus has large nerve cables that project directly to and from the orbitofrontal and medial prefrontal cortices (Öngür and Price 2000). These brain regions became active in some of our subjects, but not all of them. This variation may be due to difficulties with fMRI technology or because our subjects were in slightly different moods that activated somewhat different brain regions. Group analyses of the sorts we performed would not uncover these subtle individual variations.

44
. Dickinson 1955, #632.

4. Web of Love: Lust, Romance, and Attachment

1
. Shakespeare 1936,
Love’s Labors Lost,
act IV, scene iii, line 341.

2
. H. Fisher 1998; H. Fisher et al. 2002a; H. Fisher et al. 2002b.

3
. H. Fisher 1989, 1992, 1998, 1999.

4
. Hamill 1996, p. 32.

5
. Tennov 1979; Hatfield and Rapson 1996.

6
. Jankowiak 1995.

7
. Bell 1995.

8
. Rebhun 1995, p. 253.

9
.·Rebhun 1995, p. 254.

10
. Animal studies indicate that several brain structures are associated with the sex drive and sexual expression, including the medial amygdala, medial preoptic area, paraventricular nucleus, and the periaqueductal gray (Heaton 2000). Using fMRI, Arnow and colleagues report that when male subjects look at erotic video material, they show strong activations in the right subinsular region including the claustrum, left caudate and putamen, right middle occipital/ middle temporal gyri, bilateral cingulate gyrus, and right sensorimotor and premotor regions, whereas lesser activation occurs in the right hypothalamus (Arnow et al. 2002). Beauregard and colleagues also measured brain activation (using fMRI) in men as they viewed erotic film excerpts (Beauregard et al. 2001). Activations occurred in limbic and paralimbic structures, including the right amygdala, right anterior temporal pole, and hypothalamus. Using fMRI, Karama and colleagues recorded brain activity while men and women viewed erotic film excerpts (Karama et al. 2002). The blood oxygen level dependent (BOLD) signal increased in the anterior cingulate, medial prefrontal cortex, orbitofrontal cortex, insula and occipitotemporal cortices, as well as in the amygdala and the ventral striatum. Men also showed activation in the thalamus and significantly greater activation than women in the hypothalamus, specifically in a sexually dimorphic area associated with sexual arousal and behavior. In another experiment, researchers measured brain activity among eight men as these subjects experienced orgasm. Blood flow
decreased
in all regions of the cortex except one region of the prefrontal cortex, where it dramatically increased (Tiihonen et al. 1994). Perhaps this decreased activity explains why one becomes almost totally unconscious of the world at large during orgasm.

11
. Arnow et al. 2002.

12
. Farb 1983.

13
. Edwards and Booth 1994; Sherwin 1994.

14
. Van Goozen et al. 1997.

15
. Edwards and Booth 1994.