title: Short alleles, bigger smiles? The effect of 5-HTTLPR on positive emotional expressions.
abstract: The present research examined the effect of the 5-HTTLPR polymorphism in the serotonin transporter gene on objectively coded positive emotional expressions (i.e., laughing and smiling behavior objectively coded using the Facial Action Coding System). Three studies with independent samples of participants were conducted. Study 1 examined young adults watching still cartoons. Study 2 examined young, middle-aged, and older adults watching a thematically ambiguous yet subtly amusing film clip. Study 3 examined middle-aged and older spouses discussing an area of marital conflict (that typically produces both positive and negative emotion). Aggregating data across studies, results showed that the short allele of 5-HTTLPR predicted heightened positive emotional expressions. Results remained stable when controlling for age, gender, ethnicity, and depressive symptoms. These findings are consistent with the notion that the short allele of 5-HTTLPR functions as an emotion amplifier, which may confer heightened susceptibility to environmental conditions.
authors.affiliation: School of Education and Social Policy, Department of Psychology, Northwestern University.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Haase
authors.affiliation: Swiss Center for Affective Sciences, University of Geneva.
authors.forename: Ursula
authors.initials: U
authors.lastname: Beermann
authors.affiliation: Osher Center for Integrative Medicine, University of California, San Francisco.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Saslow
authors.affiliation: Department of Psychology, Arizona State University.
authors.forename: Michelle N
authors.initials: MN
authors.lastname: Shiota
authors.affiliation: School of Psychological Science, Oregon State University.
authors.forename: Sarina R
authors.initials: SR
authors.lastname: Saturn
authors.affiliation: Department of Psychology and Institute for Personality and Social Research, University of California, Berkeley.
authors.forename: Sandy J
authors.initials: SJ
authors.lastname: Lwi
authors.affiliation: Department of Psychology and Institute for Personality and Social Research, University of California, Berkeley.
authors.forename: James J
authors.initials: JJ
authors.lastname: Casey
authors.affiliation: Department of Psychology and Institute for Personality and Social Research, University of California, Berkeley.
authors.forename: Nguyen K
authors.initials: NK
authors.lastname: Nguyen
authors.affiliation: Private Practice.
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Whalen
authors.affiliation: Department of Psychology and Institute for Personality and Social Research, University of California, Berkeley.
authors.forename: Dacher
authors.initials: D
authors.lastname: Keltner
authors.affiliation: Department of Psychology and Institute for Personality and Social Research, University of California, Berkeley.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Levenson
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D003863:Depression / Q000235:genetics; D004644:Emotions; D054541:Family Conflict / Q000523:psychology; D005260:Female; D005838:Genotype; D006801:Humans; D007845:Laughter / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012904:Smiling / Q000523:psychology; D018454:Spouses / Q000523:psychology; D055815:Young Adult
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins