Individual Response Stereotype

Research and application in sport and exercise psychology (SEP) has relied heavily on psychophysiological applications. Heart rate (HR), blood pressure (BP), skin conductance (SC), and measurement of brain  activity  through  sophisticated  techniques such  as  positron-emission  tomography  (PET), electroencephalography  (EEG)  and  magnetoencephalography  (MEG),  and  functional  magneticresonance  imaging  (fMRI)  are  only  a  few  of  the many  psychophysiological  measures  that  have been  successfully  used  to  better  understand  psychological  phenomena  and  clarify  mechanisms  in exercise  and  sport  settings.  For  instance,  studies examining  the  relationship  between  arousal  and performance in sport have relied heavily on HR in order to classify individual performance at various levels  of  physiological  activation  or  arousal.  This area of research has led to the idea that individuals perform best when they are at an optimal level of arousal, not too over and not too under-aroused. Physiological  measures  have  also  been  employed in  exercise  psychology  to  better  understand  the effects of exercise on a wide variety of psychological  and  mental  health  outcomes  including  mood, anxiety,  depression,  cognitive  function,  and  stress reactivity. In all of these studies, subtle changes in sensitive  physiological  measures  are  used  to  infer changes  in  readiness  to  perform  or  psychological state. These subtle physiological responses are believed to be a function of the demands of a situation  or  particular  stimuli,  an  individual’s  predisposition  to  respond  in  a  specific  fashion,  and  the interaction  between  the  two.  Individual  response stereotypy  (IRS),  or  the  tendency  of  individuals to  evidence  particular  physiological  response  patterns  from  one  condition  or  situation  to  another, is  an  important  consideration  in  all  studies  or applications  incorporating  psychophysiological measures.  The  construct  of  IRS,  also  referred  to as  autonomic  response  patterning,  has  led  to  a growing  recognition  that  the  psychological  and health  significance  of  certain  psychophysiological states are better reflected by the overall pattern of activity  across  multiple  measures  of  physiological state, rather than from an acute response or sensitive  change  across  only  one  or  a  select  group  of response  domains,  such  as  fluctuations  in  HR  or SC.  Complex  patterns  of  physiological  responses, which are determined by multiple factors, are thus best studied by incorporating multiple measures of physiological responding.

According to IRS, some individuals will respond to  certain  situations  or  conditions  (e.g.,  anticipation of an upcoming event, performance of a difficult  cognitive  task,  drawing  of  blood  from  the finger, rest) with the greatest degree of activity in the same physiological measure, regardless of the situation  or  stressor.  This  is  particularly  relevant for studies or applications that rely only on a few or unitary situations and response measures. As an example, in the area of stress reactivity, researchers  have  been  interested  in  determining  whether exercise  or  fitness  are  associated  with  blunted  or altered  cardiovascular  responses  to  stress.  When assessing  BP  responses  to  stress  following  acute aerobic  exercise,  it  is  important  to  determine  not only baseline BP values (in order to assess change in stress-related BP following exercise) but also any individual difference variables that might influence BP responding. Individuals with borderline hypertension  or  essential  hypertension  tend  to  respond to  stressful  situations  with  greater  increases  in BP,  particularly  when  compared  to  normotensive individuals.  Assessing  hypertension  status  would therefore be important. It is also important to note that individuals differ widely in both resting (tonic) and  task-related  (phasic)  physiological  responses. Understanding  the  factors  that  predispose  some individuals to respond in unique ways helps inform the design of research studies as well as understand for  whom  and  under  what  situations  one  person may perform optimally or realize the greatest benefits from exercise. This individual, unique pattern of responding has led to IRS being conceptualized as a physiological trait, or an enduring disposition of the body to show specific elicited physiological states or responses.

Although  not  all  studies  are  in  agreement, the  notion  of  IRS  points  to  several  important implications.  First,  it  is  important  to  realize  that individuals do not vary haphazardly in their physiological  reactivity  in  a  given  response  measure, nor  do  they  vary  haphazardly  in  their  pattern  of reactivity.  Rather,  some  individuals  may  respond with  maximal  physiological  activation  in  the same response measure or to a particular stimulus while another may be considered a low responder or  nonresponder.  Also,  a  strong  tendency  exists for  a  unique  pattern  of  physiological  response  to be  reproduced  from  situation  to  situation.  This is  so  even  though  the  physiological  and  psychological  demands  of  the  different  situations  may be unrelated. Second, IRS has resulted in a better understanding  of  the  specific  situational  factors, familiarity with the situation, and range of behavioral  choices  that  contribute  to  the  expression  of physiological responses. These factors can be used to  strengthen  future  experimental  designs  and justify  caution  in  oversimplifying  physiological measures.  Future  studies  should  aim  to  elucidate the  specific  determinants  of  these  unique  patterns of response and consider IRS and situational demands simultaneously. The problem of IRS does not  currently  appear  to  be  a  serious  concern  as long as careful consideration is given to the number and selection of physiological responses to be measured  in  psychophysiological  studies.  Also,  a focus on IRS highlights the importance of studying individual differences in SEP research.


  1. Davis, R. C. (1957). Response patterns. Transactions of the New York Academy of Sciences, 19, 731–739.
  2. Lacey, J. I. (1956). The evaluation of autonomic responses: Towards a general solution. Annals of the New York Academy of Sciences, 67, 125–163.
  3. Stern, R. M., Ray, W. J., & Quigley, K. S. (2001).Psychophysiological recording (2nd ed.). New York: Oxford University Press.


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