in 1953, alfred kinsey's "sexual behavior in the human female" documented that, over the previous five years of sexual activity, 78% of women had orgasms in 60% to 100% of sexual encounters with other women, compared with 55% for heterosexual sex. kinsey attributed this difference to female partners knowing more about women's sexuality and how to optimize women's sexual satisfaction than male partners do. similarly, studies by several scholars, including masters and johnson, concluded that lesbian sexual behaviors more often have qualities associated with sexual satisfaction than their heterosexual counterparts, or that female partners are more likely to emphasize the emotional aspects of lovemaking. masters and johnson's 1979 study on lesbian sexual practices concluded that lesbian sexual encounters include more full-body sexual contact, rather than genital-focused contact, less preoccupation or anxiety about achieving orgasm, more sexual assertiveness and communication about sexual needs, longer lasting sexual encounters and greater satisfaction with the overall quality of one's sexual life.