+OK 5750 octets Received: from smtp03.nwnexus.com (smtp03.nwnexus.com [206.63.63.41]) by mail3.halcyon.com (8.8.8/8.8.8) with ESMTP id QAA10819 for ; Mon, 26 Apr 1999 16:50:24 -0700 (PDT) Received: from mc.egroups.com (mc.egroups.com [207.138.41.138]) by smtp03.nwnexus.com (8.8.8/8.8.8) with SMTP id QAA22740 for ; Mon, 26 Apr 1999 16:49:45 -0700 (PDT) Received: from [127.0.0.1] by mc.egroups.com with NNFMP; 26 Apr 1999 23:49:44 -0000 Mailing-List: contact h-bd-owner@egroups.com X-Mailing-List: h-bd@egroups.com X-URL: http://www.egroups.com/list/h-bd/ Delivered-To: listsaver-egroups-h-bd@egroups.com Received: (qmail 1769 invoked by uid 7770); 26 Apr 1999 23:49:42 -0000 Received: from romeo.its.uwo.ca (129.100.2.60) by vault.egroups.com with SMTP; 26 Apr 1999 23:49:42 -0000 Received: from julian.uwo.ca by romeo.its.uwo.ca with ESMTP id TAA03256; Mon, 26 Apr 1999 19:49:41 -0400 (EDT) X-Authentication-Warning: romeo.its.uwo.ca: Host 6434aa.sscl.uwo.ca [129.100.38.127] claimed to be julian.uwo.ca Message-ID: <3724FE04.CF5DAF94@julian.uwo.ca> Date: Mon, 26 Apr 1999 20:00:05 -0400 From: "J. P. Rushton" X-Mailer: Mozilla 4.04 [en] (Win95; I) MIME-Version: 1.0 To: h-bd@egroups.com Subject: [h-bd] Brain size/IQ Mini Review Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Status: Here's the handout for my presentation at the forthcoming meeting of physical anthropologists. As you will see, the widely touted negative correlation between MRI brain size and IQ is put in context. This is a quick mini-review of 8 very recent studies Sincerely, Phil Rushton (http://www.bookworld.com/rushton) Brain Size and Cognitive Ability: A Review With New Evidence [Presented at the 1999 Annual Meeting of the American Association of Physical Anthropologists, Columbus, Ohio, April 28 - May 1, 1999] J. Philippe Rushton Department of Psychology, University of Western Ontario, London, Ontario, Canada Telephone: 519-661-3685; Fax: 519-850-2302; E-mail: Rushton@julian.uwo.ca Modern research employing Magnetic Resonance Imaging (MRI), which creates a three- dimensional image of the brain in vivo, confirms a correlation between brain size and IQ. Rushton and Ankney (1996, Psychonomic Bulletin and Review, 3, 21-36) reviewed the evidence and found an overall correlation of 0.44 between MRI measured brain size and IQ in 8 separate studies. Lower, but still significant, correlations are found between external head size and IQ (r = 0.20). Additional MRI and head size studies have since confirmed these relationships, as shown in the annotated reference list. As such, these data confirm Van Valen's review (1974, American Journal of Physical Anthropology, 40, 417-424) estimating a correlation of about 0.30 between brain volume and cognitive ability from external head circumference. Head Circumference Measurements Furlow, F. B., Armijo-Prewitt, T., Gangestad, S. W., & Thornhill, R. (1997). Fluctuating asymmetry and psychometric intelligence. Proceedings of the Royal Society of London, B, 264, 823-829. [128 undergraduates, 60% female; r = 0.20] Rushton, J. P. (1997). Cranial size and IQ in Asian Americans from birth to age seven. Intelligence, 25, 7-20. [100 Asian American 7-year-olds, 54% female; r = 0.20] Summary: Number of studies = 2 Total N = 228 Unweighted mean = 0.20 N-weighted mean = 0.20 Magnetic Resonance Imaging Techniques Flashman, L. A., Andreasen, N. C., Flaum, M., & Swayze II, V. W. (1998). Intelligence and regional brain volumes in normal controls. Intelligence, 25, 149-160. [90 healthy normal volunteers, 47% female; r = 0.25] Reiss, A. R., Abrams, M. T., Singer, H. S., Ross, J. R., & Denckla, M. B. (1996). Brain development, gender and IQ in children: A volumetric study. Brain, 119, 1763-1774. [69 children aged 5- to 17- years, 80% female, r = 0.46] Tan, U., Tan, M., Polat, P., Ceylon, Y., Suma, S., & Okur, A. (in press). Magnetic resonance imaging brain size/IQ relations in Turkish university students. Intelligence. [103 Turkish university students, 52% female, r = 0.40] Schoenemann, P. T. (1997). An MRI study of the realtionship beteen human neuroanatomy and behavioral ability. Unpublished dissertation, Department of Anthropology, University of California, Berkeley. [36 pairs of sisters, age not specified; r = 0.46] Tramo, M. J., Loftus, W. C., Stukel, T. A., Green, R. L., Weaver, J. B., & Gazzaniga, M. S. (1998). Brain size, head size, and intelligence quotient in monozygotic twins. Neurology, 50, 1246-1252. [10 pairs of identical twins aged 24-43 years; sex unspecified; total forebrain volume, r = -.06; cortical surface area r = 0.20] Wickett, J. C., Vernon, P. A., & Lee, D. H. (submitted). The relationships between the factors of intelligence and brain volume. Personality and Individual Differences. [34 pairs of brothers aged 20 to 35 years; r = 0.35, corrected r = 0.50] Summary: Studies = 6 Total N = 422 Range of r = -.06 to 0.46 Unweighted mean = 0.31 N-weighted mean: 0.36 Conclusion: The correlations between cognitive ability and head size/brain size average about 0.30 and are as replicable a set of results as one will find in the behavioral sciences. ------------------------------------------------------------------------ eGroups Spotlight: "Kosovo-Reports" - Direct reports from Kosovo/Serbia/Yugoslavia. http://clickhere.egroups.com/click/5 eGroup home: http://www.eGroups.com/group/h-bd http://www.eGroups.com - Simplifying group communications .