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                  Subject                Psychology 
                  Paper No and Title      Paper No. 5: Personality Theories 
                  Module No and Title    Module No. 33: Physiological approaches to personality 
                  Module Tag             PSY_P5_M33 
                                                                                                    
                  TABLE OF CONTENTS   
                  1.  Learning Outcomes 
                  2.  Introduction: Physiological Approach to Personality 
                  3.  Physiological Measures in Personality Research 
                      3.1 Galvanic Skin Response 
                      3.2 Cardiovascular Activity 
                      3.3 Brain Activity 
                  4.  Physiological Based Theories of Personality 
                      4.1 Extraversion-Introversion 
                      4.2 Sensation seeking 
                      4.3 Morningness-Eveningness 
                      4.4 Neurotransmitters and personality 
                  5.  Limitations 
                  6.  Summary 
      Psychology                    Paper No. 5: Personality Theories 
                                    Module No. 33: Physiological approaches to personality 
                   
                                                                                 
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                       1.  Learning Outcomes 
                       After studying this module, you shall be able to 
                               Conceptualize personality as in early physiological approaches  
                               Learn about the physiological measures of personality 
                               Evaluate physiologically based personality theories 
                       2. Introduction 
                       The philosophical traditions since time immemorial are intrigued by the mind-body problem. This 
                       debate  that  has  been  passed  down  the  centuries  tries  to  narrow  down  the  physical  and 
                       psychological  experiences  of  humans.  While  a  league  of  people  believe  in  the  independent 
                       existence of the two, another large group of people research the co-dependence and co-existence 
                       of the mind and the body. In wake of modern technologies, a tremendous shift of focus has been 
                       observed while addressing the biological bases of psychological constructs. 
                       Many modern psychologists believe that differences in bodily processes result in differences in 
                       personality. The roots of this tradition of highlighting physiology in personality can be traced 
                       back to Hippocrates (c.460-c.370 B.C.). 
                       The  Four  Temperaments:  According  to  Hippocrates,  personality  is  formulated  through 
                       combination of the four body humors namely blood, yellow bile, black bile and phlegm. His 
                       proto-psychological theory suggests that there are fundamentally four types of personality types 
                       namely-sanguine, phlegmatic, choleric and melancholic 
                                                                                          
                                                            Fig.1. Illustration of Hippocrates’ typology 
                       William  Herbert  Sheldon  pioneered  in  establishing  the  biological  basis  of  personality.  He 
                       developed  somatypes  to  categorize  individuals  based  on  their  physiques.  This  approach  to 
                       personality comes under the type theories.  
        Psychology                             Paper No. 5: Personality Theories 
                                               Module No. 33: Physiological approaches to personality 
                        
                                                                                                                        
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                                                                                      Fig 2: William Herbert Sheldon 
                                 Having  studied  a  large  number  of  people  Sheldon  narrowed  down  to  three  broad  types  of 
                                 personalities- 
                                 •  Ectomorphic: characterized as linear, thin, usually tall, fragile, lightly muscled, flat chested and 
                                              delicate; described as cerebrotonic inclined to desire isolation, solitude and concealment; 
                                              and being tense, anxious, restrained in posture and movement, introverted and secretive. 
                                 •  Mesomorphic: characterized as hard, rugged, triangular, athletically built with well developed 
                                              muscles, thick skin and good posture; described as somatotonic inclined towards physical 
                                              adventure  and  risk  taking;  and  being  vigorous,  courageous,  assertive,  direct  and 
                                              dominant. 
                                 •  Endomorphic: characterized as round, usually short and soft with under-developed muscles and 
                                              having  difficulty  losing  weight;  described  as  viscerotonic  enjoying  food,  people  and 
                                              affection; having slow reactions; and being disposed to complacency. 
                                                                                       
                                                                                           Fig 3- Sheldon’s Typology 
            Psychology                                               Paper No. 5: Personality Theories 
                                                                     Module No. 33: Physiological approaches to personality 
                                  
                                                                                 
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                       Typology of personalities can be also found in ancient Indian philosophy. 
                       The Sankhya school of Hindu philosophy defines three gunas or virtues. Dominance and balance 
                       of  these  gunas  are  manifested  as  what  we  call  as  personality  in  modern  times.  However, 
                       according to this tradition nothing is cent percent defines by only one type of virtue.  
                        
                                    
                                                                Fig 4: The three gunas 
                       Human behavior categorization according to this is as follows: 
                               Satwa - is the quality of balance, harmony, goodness, purity, universalizing, holistic, 
                                constructive, creative, building, positive, peaceful, virtuous. 
                               Rajas- is the quality of passion, activity, neither good nor bad and sometimes either, self 
                                centeredness, egoistic, individualizing, driven, moving, dynamic. 
                               Tamas-  is  the  quality  of  imbalance,  disorder,  chaos,  anxiety,  impure,  destructive, 
                                delusion, negative, dull or inactive, apathy, inertia or lethargy, violent, vicious, ignorant. 
                        
        Psychology                             Paper No. 5: Personality Theories 
                                               Module No. 33: Physiological approaches to personality