Over the years, cardiologists have been impressed by an association between ischaemic heart disease and a certain personality configuration (Dumbar, 1947; Osler, 1910). However, systematic research in this area only began in the 1950s, when M. Friedman and R. Rosenman observed the similarity in behavioral characteristics of their young patients with ischaemic heart disease (Friedman & Rosenman, 1974). This constellation of attributes was called Type A Behavior Pattern and was described as repressed hostility, achievement orientedness, ambition, excessive impatience, competitiveness, overactivity and a continuous sense of time urgency.

    Physiological changes are believed to accompany the behavioral hyperresponsivity of the Type A, including elevations in plasma catecholamines and hemodynamic processes such as systolic blood pressure and heart rate. Such physiological hyperreactivity, it has been argued, may serve as the mediating mechanism whereby Type A Behavior enhances the risk of cardiovascular pathology (Contrada, Glass, Krakoff & Krantz, 1982; Lawler, Rixse & Allen, 1983; Muranaka, Lane, Suarez, Anderson, Suzuki, & Williams, 1988).

    The hypothesis of the cardiovascular hyperreactivity to stress as one of the mechanisms involved in the origin of cardiovascular disease has promoted several trends of research in current psychophysiology. One of these approaches has focused on describing specific patterns of physiological responses associated with active coping behavior (Julius, 1982; Obrist, 1985). In this respect, Obrist (1985) found that DBP changes least in those individuals evidencing the greatest myocardial and SBP changes, under conditions which maximize beta-adrenergic effects such as shock avoidance. These results suggested that increased beta-adrenergic excitation resulted not only in increased myocardial performance but also in vascular vasodilatation. "It is as if there is a trade-off in such reactive individuals between adrenergic vasodilatory and constrictive effects, resulting in little change in vascular resistance" (pp. 673).

    Linking Obrist's model with the literature on Type A Behavior Pattern we have to recognize that the numerous studies on the physiological concomitants of this behavior pattern have led to inconsistent findings. It seems that the reported findings depend on the registered autonomic response, the nature of the experimental condition, and on the measurement instrument used to assess the Type A Behavior Pattern (Fichera & Andreassi, 1998; Lyness, 1993; O’Connor, Manson, O’Connor & Buring, 1995; Palmero, Codina & Rosel, 1993; Sundin, Ohman, Palm & Strong, 1995).

    Therefore, some research has been directed at identifying the particular Type A components and other psychological variables most closely associated with neuroendocrine and cardiovascular reactivity. This line of research has led to the study of the influence of several psychological traits on cardiovascular stress response. For example, various studies have analyzed the role of Locus of Control (Calvete & Sampedro, 1992; McCanne & Lotsof, 1980), Extroversion and Neuroticism (Helin, 1988; Miller, Cohen, Rabin, Skoner & Doyle, 1999; Roger & Jamieson, 1988; Schwebel & Suls, 1999), Dominance (Newton, Bone, Flores, Greenfield, 1999), and Alexithymia (Linden, Lenz & Stossel, 1996).

    In recent years, the personality trait that has been paid more attention is the construct of anger-hostility. Most of researches have shown that the anger-out factor is the one to be associated to a higher cardiovascular reactivity, especially when a provocation element is present (Lai & Linden, 1992; Landeta, Barrenetxea, Corral & Otero, 1998, Siegman, Anderson, Herbst, Boyle & Wilkinson, 1993). However, results are inconclusive and some alternative hypothesis are being tested currently. For instance, some researchers are trying to combine the expression of hostility profiles with the ones of subjective experience of hostility and social desirability, suggesting that some specific combinations of psychological variables may associate with a very high cardiovascular reactivity (Bongard, Absi & Lovallo, 1998; Burns, 1995).

    From this complex body of literature, a different construct that may characterize the coronary-prone personality has been hypothesized. This pattern was described as an assertiveness deficit (Morrison, Bellack & Manuck, 1985) or psychosocial vulnerability (Hardy & Smith, 1988), and includes increased social anxiety, an inappropriate coping response to interpersonal distress and a negative cognitive set (Linden & Feuerstein, 1983). This construct has been paid little attention because of the fact that the researcher’s efforts in the late years have been mainly focused on the mentioned construct of anger-hostility. Anyway, the existence of this risk pattern would be coherent with the recent results reported in relation to the role of Social Support on the cardiovascular reactivity to stress (Fontana, Diegnan, Villeneuve & Lepore, 1999; Lepore, 1998; Roy, Steptoe & Kirschbaum, 1998).

    Although some of the above mentioned psychological variables have been found to be related to cardiovascular reactivity, in general, there is presently insufficient evidence to draw any conclusions, and further investigation is definitely warranted. In this sense, it would be desirable to include measures of multiple psychological variables that are relevant to the experimental condition in each study (Houston, 1986; Jorgensen, Johnson, Kolodzief & Schreer, 1996).

    Furthermore, it is very unlikely that a psychological variable will be related to reactivity in every situation and, in consequence, we should employ conditions that evoke pathologic trends in cardiovascular reactivity. As Steptoe (1985) pointed out, an appropriate approach to task selection is to base the choice on the personality factors or psychosocial environments that are characteristic of the disease group under investigation. The aim is to devise experimental procedures which mobilize the specific psychological processes thought to be important in the disorder. Thus, linking this perspective to the hypothesis of psychosocial vulnerability, an interpersonal stress situation such as an interview seems to be a useful approach. As some authors have argued, the interview may be a more ecologically valid indicator of the individual's physiological responses to the daily life stressors (Dimsdale, Stern & Dillon, 1988).

    However, there has been little research assessing the physiological and subjective responses during stressful interviews. Some relevant studies in this context are the researches based on the Structured Interview (Rosenman, 1978), which involves a structured set of questions and a certain provocative style imposed by the interviewer (for instance, Blumenthal, Lane, & Williams, 1983), interviews about areas of psychic conflict (Svensson & Theorell, 1982; Vitaliano, Russo, Bailey, Young & McCann, 1993), the Stress Interview (Dimsdale, Stern & Dillon, 1988), and assessments during tests of social competence and role-playing (Linden & Feuerstein, 1983; Delamates & cols., 1989; Waldstein, Neumann, Burns & Maier, 1998).

    Based on the literature just cited, the current study represents an attempt to increase our knowledge about the relationship between psychological variables and physiological responses to an interpersonal encounter. With this purpose, the following objectives were established: (1) to assess the physiological and subjective concomitants of a stressful interview in order to identify different response patterns in accordance with Obrist's hypothetical model, and (2) to determine which psychological variables contribute most to the prediction of these patterns.

    100 healthy student volunteers (50 male and 50 female) composed the sample. The mean age was 21.45 yr. (SD=4.21).

    The designed interview has three different steps:

(1) Presentation Stage. The interviewer asks the individual to talk about him/herself and his/her general life: "Please tell me something about yourself and your life, i.e., your name, family, daily activities, hobbies and plans for the future."

(2) Experiential Stage. In the second stage, the individual is asked to relate a painful and frustrating recent life event. The interviewer encourages the participant to emphasize the subjective aspects of the experience: "Please talk to me in some detail about a painful and frustrating experience that has happened to you recently. I would like you to emphasize the feelings you experienced about that event."

(3) Self-Assessment Stage. Finally, the individual has to assess his/her own personality traits: "Please, tell me what you think are the three most positive traits and the three most negative traits in your personality."

    A clinical psychologist performed all of the interviews. Preliminary training was carried out to develop a homogeneous structure of the interview and to minimize the interviewer's influence.

    Measurements of heart rate, peripheral vascular activity, blood pressure, breathing and skin conductance were used to assess physiological reactivity.

    Systolic and diastolic blood pressure were measured with a digital DS-91 Model device, the arm cuff was placed on the right arm and pressure values were mechanically recorded. The other physiological variables were registered by a Grass Model 7 Polygraph equipped with Grass Model 7P122 Low Level DC Amplifiers.

    Pulse Amplitude and Heart Rate were measured with a Grass Transmittance Photoelectric Pulse Transducer Model PTTL-1 positioned on the right earlobe. Amplitudes were expressed in milivolts. Skin resistance was recorded with two Grass Ag/AgCl fingertip electrodes, attached to the fore, and middles nondominate fingers and was subsequently converted into Skin Conductance (micromhos).

    Respiration was measured using a Grass Model TCT 1R Thermistor placed at the nostril. This measure was recorded to verify that major respiratory maneuvers were not a consistent response to the interview (Jennings & Choi, 1981).

    All the measures were digitized with a Data Translation DT 2814 A/D converter to a rate of 30 samples per minute and were processed by an IBM PC computer.

    The subjective concomitants of the interview were assessed with the ESE and EAS (Calvete, 1992). These scales contain several subscales: stress, positive arousal, negative arousal, anger, active coping, passive coping and fatalism, and control perception. Cronbach's Alpha coefficients for all the scales ranged between .73 and .88.

    Type A Behavior Pattern was measured with the Spanish version of the JAS (Jenkins Activity Survey) validated by De Flores, Valdes & Sans (1982). The JAS include four major components: the Type A scale, factor S (speed and impatience), factor J (job involvement), and factor H (hard driving and competitive).

    The Locus of Control was identified by the use of Rotter's Locus of Control Scale (Rotter, 1966), that is a measure of the extent to which an individual believes that reinforcements in his life are under his control and are contingent upon his behavior (internal locus of control), as opposed to believing that reinforcements are not under his control and are not contingent upon his behavior (external locus of control).

    In addition, several personality traits were assessed with the Spanish version of the 16 PF Questionnaire (Cattell, 1988). This questionnaire includes 16 personality factors: Affectothymia (Factor A), Intelligence (B), Ego Strength (C), Dominance (E), Surgency (F), Superego (G), Parmia (H), Premsia (I), Protension (L), Autia (M), Shrewdness (N), Guilt Proneness (O), Radicalism (Q1), Self-sufficiency (Q2), Self-sentiment (Q3), and Ergic Tension (Q4).

    Participants were asked to refrain from drinking coffee, alcohol and from smoking for at least 2 hours before coming to the laboratory. All individuals fulfilled these requirements. They were told that they were going to be interviewed by a clinical psychologist and that we wanted to assess their physiological and subjective responses during the interview that lasted about 15-20 minutes. Upon arrival and following familiarization with the instrumentation, the participant was seated in a comfortable chair, the transducers and electrodes were attached and blood pressure was measured. A 20-min. pre-stressor adaptation period was followed by the interview. Blood pressure was measured again immediately after the interview and the individual filled in the ESE and EAS scales, regarding his/her feelings during the interview. The other questionnaires were completed at home.

    Data Reduction Samples of autonomic activity were recorded at minute 19-20 of the adaptation period and during the first minute of each interview stage. Samples from the interview were averaged to represent one value for skin conductance, pulse amplitude, heart rate and respiration rate for the total interview. In the same way, data from adaptation period minute 19-20 were averaged (baseline).

    The SPSS was used for all statistical analyses. A cluster analysis was carried out to search for relatively homogeneous groups of stress responses. Mean change scores for HR, pulse amplitude, SBP, DBP, skin conductance level and subjective scales scores were included in a QUICK CLUSTER procedure based on nearest centroid sorting. That is, a case is assigned to the cluster for which the Euclidean distance between the case and the center of the cluster (centroid) is smallest. Cluster centers were estimated from the data and, prior to the analysis, all variables were converted into Z scores.

    A DISCRIMINANT analysis was used to determine which psychological variables distinguish most between the three reactivity patterns. Linear combinations of the predictor variables are formed and serve as the basis for classifying cases into one of the three groups. Prior to the analysis, Box's M Test was performed to test equality of the groups covariance matrices. A stepwise selection algorithm using minimization of Wilks' Lambda was employed for selection of predictor variables.

    A solution of three clusters provided the most interpretable and homogeneous groups. The final cluster centers or average values of the variables are shown in Table 1.

    To assess the between-cluster to within-cluster variability, a one-way analysis of variance for each of the variables was computed. As can be observed in Table 1, individuals in the three groups seem to be different in HR, pulse amplitude, SBP, DBP and skin conductance level changes, and in positive arousal, negative arousal and active coping.

    Group 1 contains half the participants (n=45) and consists of a moderate HR acceleration (M=+16.78), great vasoconstriction (M=-0.719), and increase of DBP (M=+6.07).

    Thirty-nine individuals were assigned to Group 2. This response pattern consists in the greatest skin conductance increase (M=+0.71) together with a low cardiovascular reactivity and low scores in positive arousal and active coping.

    Finally, Group 3 is the smallest (n=12), has the highest responses in HR (M=+22.5) and SBP (M=+15.58), the highest scores in subjective arousal (M=5.00) and use of active coping strategies (M=11.80). Further, this pattern shows a decrease in DBP reactivity (M=-5.83) and a small SCL response (M=+0.24).

    Sex, 16 Personality Factors, Locus of Control and the four components of the JAS were included in the Discriminant analysis. Table 2 lists the action taken (entry or removal) for each step and shows the resulting Wilks' Lambda, its significance level and the major statistics for the two discriminant functions. The square root of the canonical correlations are the proportion of total variability explained by differences between groups and, consequently, both functions account for similar between-group variability (43%, 41.87%) and have been considered simultaneously for classification of individuals into groups.

SUMMARY TABLE

CANONICAL DISCRIMINANT FUNCTIONS

TABLE 3
STANDARDIZED CANONICAL DISCRIMINANT FUNCTION COEFFICIENTS AND GROUP CENTROIDS

GROUP CENTROIDS

    Table 3 contains the two sets of standardized discriminant function coefficients and the group means for the two functions. Group 1 has a positive mean for Function 1 and a negative mean for Function 2, Group 2 has a negative mean for Function 1 and a slightly positive one for Function 2, while Group 3 has the highest positive means for both functions. Table 4 shows that the model classifies 87 out of 96 cases (90.62%) correctly.

TABLE 4
CLASSIFICATION RESULTS

    The univariate tests for the individual predictor variables were examined to get a better understanding of where the differences between the three groups' scores occurred. As indicated in Table 5, univariate F tests reveal significant effects for sex, ego strength (C), locus of control, self-sufficiency (Q2), schrewdness (N), parmia (H) and self-sentiment (Q3).

TABLE 5
PSYCHOLOGICAL CHARACTERISTICS FOR THE THREE GROUPS

    A post hoc Scheffé Test with an alpha of 0.05 was used to discover which two subgroups differed when the overall F-value indicated that the three groups had unequal means. The Scheffé method is conservative for pairwise comparisons of means, and requires larger differences between means for significance than most other methods. From group 3, 11 of the 12 individuals are men. For Factor C (Emotional Instability) group 2 individuals obtain higher scores than group 1 individuals. Group 3 individuals show a lower score for Factor H (Social Inhibition) and Factor N (Shrewdness). According to the Scheffé Test, the difference is significant in the first factor with regard to group 3 and the second factor with regard to group 1. On the other hand, group 3 individuals have the highest scores on Factor Q2 (Self-Sufficiency) and Factor Q3 (High Strength of Self-Sentiment). Finally, this group shows a tendency towards internality in Locus of Control, and the difference is significant with regard to group 2. There are not significant univariate differences for other predictor variables included in the model such as Type A Behavior Pattern, Dominance, Suspiciousness, Premsia, and Competitiveness.

    The fact that the clusters are based not only on physiological parameters but also on emotional reactions raises the possibility that the psychological factors predict group membership because they are correlated with the emotional reactions during the interview.

TABLE 6
CORRELATIONS BETWEEN PSYCHOLOGICAL FACTORS AND SUBJECTIVE SCALES

* p < .01

    In order to evaluate such a possibility, the correlations between the psychological predictor factors and the scores on subjective stress scales were obtained. As can be observed in Table 6, the correlations are not significant, except in the case of social inhibition with subjective stress. Consequently, the predictor value of such factors does not seem to be based on an association with the subjective components of stress.

    It has traditionally been suggested that a better specification of person-environment interactions would improve the relationship between personality variables, and physiological parameters (Christenfeld, Glynn, Kulik & Gerin, 1998). Thus, if a psychosocial vulnerability is postulated as a psychological risk factor for cardiovascular disorders, a social encounter seems to be a good strategy to assess the physiological concomitants of such vulnerability.

    In the present study an attempt was made to link both perspectives: (1) The assessment of physiological reactivity in interpersonal interactions, and (2) the identification of psychological variables that may influence the individual's attitude toward such interpersonal encounters and, consequently, his/her physiological responses.

    Other authors were impressed by the dramatic blood pressure elevations elicited during social encounters (Dimsdale and cols., 1988; Vitaliano and cols., 1993). Our study leads to similar findings not only in blood pressure but also in other physiological parameters (pulse amplitude, HR, Skin Conductance level), and further the designed interview appears to be a powerful instrument in eliciting different reactivity patterns.

    The Cluster Analysis revealed three different response patterns to interpersonal stress. Only two of these can be described as cardiovascular reactives: Group 1 and Group 3. The first is exhibited by most of the individuals of the sample and is characterized by a greater vasoconstriction, an increase in DBP and moderate HR acceleration. The other cardiovascular reactive pattern (Group 3) appears in few individuals and consists in the greatest HR and SBP elevations together with the use of active coping strategies and a decrease in DBP.

    According to Obrist (1985), there is a predisposition on the part of some individuals to be adrenergically hyperreactive and those individuals evidencing greater myocardial reactivity also evidence greater SBP reactivity. In contrast, the DBP tends to be influenced in somewhat the reverse manner, and with individuals where beta-adrenergic influences are less, the DBP increase more. The hypothetical beta-adrenergic excitation results not only in increased myocardial performance but also in vascular vasodilatation. Therefore, this tentative model suggests that our Response Pattern 3 can reflect a hypertensive risk factor. Although these findings demand a replication with more accurate blood pressure measurements, the dichotomy between SBP and DBP reactivities has been founded in other studies and, for example, in a research of Linden and Feuerstein (1983), in comparison to normotensives, hypertensives showed no increase in diastolic blood pressure during an interpersonal stress situation.

    The present study also set out to identify psychological variables with a high predictive value over the stress response patterns. The discriminant analysis selected twelve variables: sex, emotional instability, locus of control, self-sufficiency, schrewdness, parmia, self-sentiment, Type A Behavior Pattern, competitiveness, suspiciousness, premsia, and dominance.

    These variables permit the psychological description of individuals expressing the beta-adrenergic hyperresponsivity (Pattern 3). They are men emotionally less stable, at the mercy of their feelings (Factor C) and with a predisposition for emotional sensitivity and fastidiousness (Factor I). Regarding social relationships, these individuals score low on Factor H and Factor N, appearing as timid, socially inhibited and clumsy. Cattell (1973) defined the negative pole of Factor H as a high sensitivity of the sympathetic nervous system leading to shyness and withdrawal from conflict. The Factor N pattern was described as beginning with insecurity or a selfish social environment that forces the individual to use selfishness as a defense.

    This social insecurity is combined with a lack of group adherence. Pattern 3 individuals are self-sufficient, and prefer their own decisions (Factor Q2). There may be a deficiency of gregariousness and a steadiness of emotion that favors dependence on the self and lack of rewarding response by others (Cattell, 1973). They are also suspicious and defensives (Factor L). Prior studies have found that individuals with repressive-defensive tendencies often display elevated physiological responses in stressful situations (Linden & Feuerstein, 1983).

    In relation to the control dimension, they show a high strength of self-sentiment, control, care of social roles and compulsion (Factor Q3). Finally they believe that reinforcements in their life are under their control and are contingent upon their behavior (internal locus of control). This aspect has been supported broadly in the literature. HR and SBP are influenced in a like manner by the degree of control which the individual has over challenging environmental events and, consequently, his/her beliefs about possibility of control will affect the response pattern (Contrada et al., 1982; Pittner, Houston, & Spiridigliozzi, 1983; Light & Obrist, 1983).

    Although the Type A Behavior Pattern has been selected into the discriminant model, its effect is contrary to what would be expected, and the risk response pattern is associated with low scores in Type A Behavior and the highest in competitiveness.

    Overall, several of the predictor variables included in the model support the hypothesis of the interpersonal deficit or lack of social competence associated with cardiovascular hyperreactivity. As other authors have suggested (Hardy & Smith, 1988; Orth-Gomer & Unden, 1990), this social competence deficit can mediate through a double mechanism:

(1) First, the deficit leads to a more stressful perception of daily social encounters and, in consequence, to a greater cardiovascular response.

(2) Second, the lack of social competence leads to less satisfactory, and sometimes fewer, social supports as an important moderator factor in the stress-disease process.

Blumenthal, J. A., Lane, J. D., Williams, R. B.Jr. (1983). Effects of task incentive on cardiovascular response in type A and type B individuals. Psychophysiology, 20(1), 63-70.

Bongard, S., Absi, M., Lovallo, W. R. (1998). Interactive effects of trait hostility and anger expression on cardiovascular reactivity in young men. International Journal of Psychophysiology, 28, 181-191.

Burns, J. W. (1995). Interactive effects of traits, states and gender on cardiovascular reactivity during different situations. Journal of Behavioral Medicine, 18(3), 279-303.

Calvete, E. (1992). Evaluación de los componentes subjetivos del estrés y su relación con los parámetros fisiológicos. Psiquis, 13 (9), 371-385.

Calvete, E. & Sampedro, R. (1991). Reactividad cardiovascular al estrés y locus de control. Análisis y Modificación de Conducta, 17 (51), 33-46.

Cattell, R. B. (1988). 16 PF, Cuestionario factorial de personalidad (adolescentes y adultos). Madrid: TEA ediciones.

Cattell, R. B. (1973). Personality and Mood by Questionnaire. San Francisco, California: Jossey-Bass.

Christenfeld, N., Glynn, L. M., Kulik, J. A. & Gerin, W. (1998). The social construction of cardiovascular reactivity. Annals of Behavioral Medicine, 20(4), 317-325.

Christensen, A. J. & Smith, T. W. (1993). Cynical hostility and cardiovascular reactivity during self-disclosure. Psychomatic Medicine, 55(2), 193-202.

Contrada, R. J., Glass, D. C., Krakoff, L. R., Krantz, D. S. (1982). Effects of Control Over Aversive Stimulation and Type A Behavior on Cardiovascular and Plasma Catecholamine Responses. Psychophysiology, 19(4), 408-419.

De Flores, T., Valdes, M. & Sans, S. (1982). Inventario de Actividad de Jenkins. Edición experimental. Madrid: TEA.

Delamates, A. M., Taylor, C. B., Schneider, J., Allen, R., Chesney, M. & Agras, W. S. (1989). Interpersonal behavior and cardiovascular reactivity in pharmacologically treated hypertensives. Journal of Psychosomatic Research, 33(3), 335-345.

Dimsdale, J. E., Stern, M. J. & Dillon, E. (1988). The Stress Interview as a tool for examining physiological reactivity. Psychosomatic Medicine, 50, 64-71.

Dumbar, F. (1947). The mind and the health. In Mind and Body: Psychosomatic Medicine, 120-145. New York: Random House.

Fichera, L. V. & Andreassi, J. L. (1998). Stress and personality as factors in women’s cardiovascular reactivity. International Journal of Psychophysiology, 28(2), 143-155.

Fontana, A. M., Diegnan, T., Villeneuve, A. & Lepore, S. J. (1999). Nonevaluative social support reduces cardiovascular reactivity in young women during acutely stressful performance situations. Journal of Behavioral Medicine, 22(1), 75-91.

Friedman, M. & Rosenman, R. (1974). Type A behavior and your heart. New York: KNOPF.

Hardy, J. D. & Smith, T. W. (1988). Cynical hostility and vulnerability to disease: Social support, life stress, and physiological response to conflict. Health Psychology, 7(5), 447-459.

Helin, P. (1988). Psychophysiological activation during performance and competition and the effects of relaxation training and running exercise. Doctoral Dissertation. University of Kuopio.

Houston, B. K. (1986). Psychological variables and cardiovascular and neuroendocrine reactivity. En K. A. Matthews, S. M. Weiss, T. Detre, T. M. Dembroski, B. Falkner, S. B. Manuck & R. B. Williams (Eds.), Handbook of stress, reactivity, and cardiovascular disease. New York: Wiley.

Jennings, J. R. & Choi, S. (1981). Type A components and psychophysiological responses to an attention-demanding performance task. Psychosomatic Medicine, 43(6), 475-487.

Jorgensen, R. S., Johnson, B. T., Kolodziej, M. E. & Schreer, G. E. (1996). Elevated blood pressure and personality: a meta-analytic review. Psychological Bulletin, 120(2), 293-320.

Julius, S. (1982). Psychophysiological evidence for the role of the nervous system in hypertension, in A. Amery et al. (Eds.), Hypertensive cardiovascular disease: Pathophysiology and treatment, Martinus Nijhoff: The Hague.

Lai, J. Linden, W. (1992). Gender, Anger expression style and opportunity for anger release determine cardiovascular reaction to and recovery from anger provocation. Psychosomatic Medicine, 54, 297-310.

Landeta, O., Barrenetxea, A., Corral, S. & Otero, J. (1998). Componente expresivo de hostilidad y reactividad cardiovascular al estrés. Ansiedad y Estrés, 4(2-3), 215-225.

Lawler, K. A., Rixse, A. & Allen, M. T. (1983). Type A behavior and psychophysiological responses in adult women. Psychophysiology, 20(3), 343-350.

Lepore, S. J. (1998). Problems and prospects for the social support- reactivity hypothesis. Annals of Behavioral Medicine, 20(4), 257-269.

Linden, W., Feuerstein, M. (1983). Essential Hypertension and Social Coping Behavior: Experimental Findings. Journal of Human Stress, 9, 22-31.

Linden, W., Lenz, J. W. & Stossel, C. (1996). Alexithymia, defensiveness and cardiovascular reactivity to stress. Journal of Psychosomatic Research, 41(6), 575-583.

Linden, W. & Long, B. C. (1987). Repression, hostility, and autonomic recovery from a laboratory stressor. Journal of Clinical Hypertension, 3, 567-578.

Light, K. C. & Obrist, P. A. (1983). Task difficult, Heart Rate Reactivity, and Cardiovascular Responses to an appetitive reaction time task. Psychophysiology, 20 (3), 301-312.

Lyness, S. A. (1993). Predictors of differences between Type A and B individuals in heart rate and blood pressure reactivity. Psychological Bulletin, 114(2), 266-295.

McCanne, T. R. & Lotsof, E. J. (1980). Locus of control and the autonomic responses associated with a visual orienting task. Physiological Psychology, 8(1), 137-140.

Miller, G. E., Cohen, S., Rabin, B. S., Skoner, D. P. & Doyle, W. J. (1999). Personality and tonic cardiovascular, neuroendocrine, and immune parameters. Brain and Behavior Immunology, 13(2), 109-123.

Morrison, R. L., Bellack, A. S. & Manuck, S. B. (1985). Role of social competence in bordeline essential hypertension. Journal of Consulting and Clinical Psychology, 53(2), 248-255.

Muranaka, M., Lane, J. D., Suarez, E. C., Anderson, N. B., Suzuki, J. & Williams, R. B. (1988). Stimulus-specific patterns of cardiovascular reactivity in type A and B individuals: Evidence for enhanced vagal reactivity in type B. Psychophysiology, 25(3), 330-338.

Newton, T. L., Bane, C. M., Flore, A. & Greenfield, J. (1999). Dominance, gender, and cardiovascular reactivity during social interaction. Psychophysiology, 36(2), 245-252.

Obrist, P. A. (1985). Beta-adrenergic hyperresponsivity to behavioral challenges: a possible hypertensive risk factor. En J.F. Orlebeke et al. (Eds.), Psychophysiology of cardiovascular control. New York: Plenum Press.

O’Connor, N. J., Manson, J. E., O’Connor, G. T. & Buring, J. E. (1995). Psychosocial risk factors and nonfatal myocardial infarction. Circulation, 92(6), 1458-1464.

Orth-Gomer, K. & Unden, A. (1990). Type A behavior, social support and coronary risk. Interaction and significance for mortality in cardiac patients. Psychosomatic Medicine, 52(1), 59-72.

Osler, W. (1910). The lumleian lecture on angina pectoris. Lancet, 1, 839.

Palmero, F., Codina, V. & Rosel, J. (1993). Psychophysiogical activation, reactivity, and recovery in Type A and Type B scorers when in a stressful laboratory situation. Psychological Reports, 73(3), 803-811.

Pittner, M. S., Houston, B. K. & Spiridigliozzi, G. (1983). Control over stress, type A behavior pattern, and response to stress. Journal of Personality and Social Psychology, 44(3), 627-637.

Roger, D. & Jamieson, J. (1988). Individual differences in delayed heart-rate recovery following stress: The role of extraversion, neuroticism and emotional control. Personality and Individual Differences, 9(4), 721-726.

Rosenman, R. H. (1978). The interview method of assessment of the coronary-prone behavior pattern. In T. Dembroski, S. Weiss, J. Shields, S. Haynes & M. Feinleib (Eds.), Coronary-prone behavior (pg. 55-69), New York: Springer-Verlag.

Rotter, J. B. (1966). Generalized expectancies for internal versus external control of reinforcement. Psychological Monographs, 80, 609.

Roy, M. P., Steptoe, A., Kirschbaum, C. (1998). Life events and social support as moderators of individual differences in cardiovascular and cortisol reactivity. Journal of Personality and Social Psychology, 75(5), 1273-1281.

Schwebel, D. C. & Suls, J. (1999). Cardiovascular reactivity and neuroticism: results from a laboratory and controlled ambulatory stress protocol. Journal of Personality, 67(1), 67-92.

Siegman, A. W., Anderson, R., Herbst, J., Boyle, S. & Wilkinson, J. (1993). Dimensions of anger-hostility and cardiovascular reactivity in provoked men. Journal of Behavioral Medicine, 15, 257-272.,

Steptoe, A. (1985). Theoretical bases for task selection in cardiovascular psychophysiology. In A. Steptoe et al. (Eds.), Clinical and methodological issues in cardiovascular psychophysiology. Berlin-Heidelberg: Springer Verlag.

Sundin, O., Ohman, A., Palm, T. & Strom, G. (1995). Cardiovascular reactivity, Type A behavior, and coronary heart disease: comparisons between myocardial infarction patiens and controls during laboratory-induced stress. Psychophysiology, 32(1), 28-35.

Svensson, J. C. & Theorell, T. (1982). Cardiovascular effects of anxiety induced by interviewing young hypertensive male subjects. Journal of Psychosomatic Research, 26, 359-379.

Vitaliano, P. P., Russo, J., Bailey, S. L., Young, H. M., McCann, B. S. (1993). Psychosocial factors associated with cardiovascular reactivity in older adults. Psychosomatic Medicine, 55(2), 164-177.