title: Authors' Response to Kaufman and Muntaner.
authors.affiliation: Centre for Philosophy of Natural and Social Science, London School of Economics, London, UK arden.rosalind@gmail.com.
authors.forename: Rosalind
authors.initials: R
authors.lastname: Arden
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Luciano
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.affiliation: Department of Psychology, University of California, Riverside, CA, USA.
authors.forename: Chandra A
authors.initials: CA
authors.lastname: Reynolds
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Pedersen
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA.
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Plassman
authors.affiliation: DepartmentofPsychology, University of Minnesota, Minneapolis, MN, USA DanishAging Research Center, University of Southern Denmark, Odense, Denmark.
authors.forename: Matt
authors.initials: M
authors.lastname: McGue
authors.affiliation: DanishAging Research Center, University of Southern Denmark, Odense, Denmark.
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
authors.affiliation: Queensland Brain Institute, University of Queensland Diamantina Institute, Woolloongabba, QLD, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Visscher