The number and types of health behaviours depending on chronotype and temperamental traits

University of Warsaw Faculty of Psychology The number and types of health behaviours depending on chronotype and temperamental traits Master Thesis in Psychology of Individual Differences (abstract) Anna Nurzynska Warsaw, 2007

This study investigated the relationship between morning and evening types and health behaviour. The hypothesis assumed that tendency towards morningness leads to a healthier lifestyle. In order to verify the hypothesis three questionnaires were used: the Morningness-Eveningness Questionnaire MEQ, Pavlovian Temperament Survey PTS, and developed by the author of this research Health Behaviour Quesionnaire HBQ. The research was carried out on a sample of 122 subjects, 54 males and 68 females between 19 and 85. In relation to research assumptions the respondents group was devided into subgroups, after taking two demographic variables: age and sex into consideration. According to received data, it was stated that chronotype differentiated between respondents with high and low scores in Health Behaviour Quesionnaire. Morning types admitted to undertaking more health behaviours than evening types. Furthermore, the research revealed that in groups undertaking intensive physical activity and consuming alcohol and tobacco were more respondents defined as evening types. These findings also confirmed the positive correlation between living a healthy lifestyle and the Pavlovian constructs of Central Nervous System properties: strength of excitation, strength of inhibition, and mobility of nervous processes. KEYWORDS: Chronotype, health behaviour, temperament.

CONTENTS: Chapter I. THEORETICAL INTRODUCTION...2 1. Chronotype as a reflection of individual differences in human circadian clock... 2 1.1. Definition and characteristics of concept... 2 1.2. Circadian rhythms and morningness-eveningness dimension... 3 1.2.1. Rhythmic changes of physiological processes depending on chronotype... 4 1.2.2. Different circadian rhythms of psychological processes in morning and evening types... 6 1.3. Relationships beetween chronotype and psychological variables... 7 2. Health behaviours... 9 2.1. Definition and classification... 9 2.2. Nutrition habits... 10 2.3. Physical activity... 12 2.4. Prophylactic and preventive behaviour... 13 2.5. Stress management... 13 2.6. Avoiding harmful substances... 14 3. Chronotype and lifestyle... 15 4. Research questions and hypotheses... 19 Chapter II. RESEARCH METHOD... 21 1. Research assumptions... 21 2. Statistical technique... 24 3. Research instruments... 24 4. Respondents... 27 5. The course of research... 28 Chapter III. DATA ANALYSIS... 29 1. Data distributions... 29 2. Lifestyle pattern in morning and evening types... 36 3. Health behaviours undertaken by different chronotypes... 37 4. Health behaviours, chronotypes and temperament dimensions... 41 5. Chronotypes and health behaviour depending on sex and age of respondents... 49 6. Summary... 52 Chapter IV. DATA INTERPRETATION... 54 1. Received outcomes and hypotheses... 54 1.1.Chronotypes and health behaviours... 54 1.2. Healthy lifestyle and chronotypes... 56 1.3. Health behaviours undertaken by different chronotypes... 57 1.4. PTS scales, health behaviour and chronotype... 60 2. Critical evaluation of research... 61 References... 63

[abstract] The number and types of health behaviours depending on chronotype and temperamental traits Chapter III. DATA ANALYSIS 1. Data distributions Figure 1 illustrates that the range of MEQ scores observed among 122 respondents was 31 83 (mean = 59.549, SD = 9.59). High scores indicate a high degree of morningness. The Kolmogorov-Smirnov test was used for testing normality of the distribution indicating value 0,669 (p>0,762; two-tailed). Morningness Eveningness Questionnaire scores distribution was slightly left-skewed (skewness 0,258, kurtosis 0,036) but did not significantly differ from normal distribution. Figure 1. Distribution of morningness eveningness scores for the 122 subjects Analyses were conducted assuming that a criterion of division between chronotypes is a distance of MEQ score of more than one standard deviation from the mean. According to this criterion intermediate types are those with MEQ scores between 50 69 which are within one standard deviation from the mean. Subjects with morning disposition have scores above one standard deviation from the mean (between 70 83) and evening types below one standard deviation from the mean (between 31 47).

TABLE 5. Summary statistics of MEQ types (Morning type, Intermediate Type and Evening Type) with respect to demographic variables: gender and sex (percentage in parentheses) CHRONOTYPE MT IMT ET TOTAL GENDER AGE WOMEN MEN MEAN & SD 20 (16,4) 14 (20,5) 6 (11,1) 48,75 (10,75) 19 34 0 35 49 >50 7 (17,5) 13 (30,2) 86 (70) 47 (69,1) 39 (57,4) 42,22 (14,51) 25 (64,1) 31 (77,5) 30 (69,8) 16 (13,1) 7 (10,3) 9 (16,6) 30,18 (10,11) 14 (35,9) 2 (5) According to criterion of division between chronotypes of more than one standard deviation from the mean, subjects were devided into three categories: morning types (16,4% of a sample), intermediate types (70% of a sample), and evening types (13,1% of a sample). Among women there is twice as many morning types as evening types, and in a group of men there is predominance of people with evening disposition. Moreover, among morning types women outnumbered men. Data in this study showed that mean ages in the whole sample differ for particular chronotypes and are much higher for people with morning disposition, which is consistent with previous literature (Adan, 1992; Paine, Bander, Travier, 2006; Wilson, 1990). In the sample of morning types there is no one from the 19 34 age group, and in the evening types sample no one aged 50 or over. Figure 2 illustrates the distribution of Health Behaviours Questionnaire scores. 0 Figure 2. HBQ scores for the 122 subjects

A distribution was slightly left-skewed (skewness -0,488, kurtosis 0,237) but closely resembling normal and indicating wide diversity in number of health behaviours undertaken by respondents and predominance of people with the lowest questionnaire outcomes. None of subjects admit to undertaking all health behaviours from HBQ. The least number of health behaviours declared by one of the respondents was 8. 2. Lifestyle pattern in morning and evening types In order to verify first hypothesis three chronotypes were compared with regard to the number of health behaviours undertaken by people with a morning and evening disposition. The mean Health Behaviour Questionnaire (HBQ) scores separately for morning, intermediate and evening types presents figure 6. Figure 6. Health behaviours depending on chronotype The mean HBQ score was the highest for people with a morning disposition (M=32,05, SD=5,46), lower for those with intermediate disposition (M=29,53, SD=7,70) and the lowest for group of subjects with evening disposition (M=24,81, SD=5,02). The relationship between MEQ types and HBQ scores was analysed by using One-Way ANOVA. Concerning the number of undertaken health behaviours there was a significant difference between chronotypes (F=4,747; df=2/121; p<0,01). NIR post hoc test showed that evening types undertake less health behaviours than intermediate and morning types (p<0,05), though no significant difference was found between groups with morning and intermediate disposition. [...]

4. Health behaviours, chronotypes and temperament dimensions Correlation analyses between scores of the three Pavlovian Temperament Survey PTS scales and HBQ scores were conducted for the whole sample and for the subsamples of men and women. Table 7 presents correlation coefficients (Pearson s r) of Health Behaviour Questionnaire scores with three temperamental dimensions. TABLE 7. Pearson r correlation coefficients computed between temperamental traits (SE, SI, MNP) and number of health behaviours (HBQ for the whole group, for females and males number of subjects in parentheses) SE SI MNP HBQ (N=122) HBQ in women (N=68) HBQ in men (N=54) 0,202* 0,230* 0,284** 0,249* 0,241* 0,273* 0,341* 0,211 0,358** **. The correlation is significant at the 0,01 level (two-tailed) *. The correlation is significant at the 0,05 level (two-tailed) Considering the whole sample there were significant positive correlations between the number of health behaviours and strength of excitation (r=0,202; p<0,025), strength of inhibition (r=0,230; p<0,011), and mobility of nervous processes (r=0,284; p<0,002). As predicted, living a healthy lifestyle is associated with the ability to continue working under intense, distracting or disturbing conditions, with the general ability to shift from one activity to another and the ability to exercise behavioural restraint. With respect to gender, in the group of women there were significant positive correlations between HBQ scores and all three PTS scales (with SE r=0,249; p<0,040; with SI r=0,241; 0,047 and with MNP r=0,237; p<0,025). In the sample of men the number of health behaviours was significantly associated with strength of excitation (r=0,341; p<0,012) and mobility of nervous processes (r=0,358; p<0,008). There was no significant correlation between HBQ scores and strength of inhibition. 5. Chronotypes and health behaviour depending on sex and age of respondents [...] Mean Morningness Eveningness scores received by men and women in each age group differed indicating that female subjects scored as more morning type than male respondents (table 11).

TABLE 11. Student's t-tests between MEQ scores received by women and men in three age groups and the total sample Age Women Men N Mean & SD N Mean & SD 19-34 23 52,43 50,00 16 (7,86) (9,18) 35-49 23 61,08 59,94 17 (7,61) (6,89) >50 22 68,22* 63,52* 21 (7,43) (5,63) Total 68 60,47 58,38 54 (9,93) (9,09) Mean MEQ score in the whole group of women was higher compared to mean in the group of men, but the difference wasn t significant (t=1,193; df=120; ns). Morningness Eveningness scores analysed by Student s independent t test, were statistically different between groups of men and women only in one age group subjects aged 50 and over (t=2,329; df=41; p<0,025). Mean Health Behaviours Questionnaire scores in total samples of men and women were also calculated and compared using Student s independent t test (table 12). TABLE 12. Student's t-tests between HBQ scores received by women and men in three age groups and the total sample Age Women Men N Mean & SD N Mean & SD 19-34 23 30,86* 23,93* 16 5,41 5,75 35-49 23 30,21 27,76 17 6,59 10,01 >50 22 30,50 30,80 21 5,97 8,25 Total 68 30,52 27,81 54 5,92 8,57 Mean HBQ score in the whole group of women was higher compared to mean in the group of men, but the difference wasn t significant (t=1,981; df=90,576; ns). Moreover, women participants aged 19 to 34 years were more likely to declare living a healthy lifestyle (t=3,834; df=37; p<0,001) compared to men participants.

The number of health behaviours undertaken by each chronotype was compared separately for males and females (figure 7). Figure 7. HBQ means received by three chronotypes depending on gender In the group of women One Way ANOVA revealed no statistically significant differences between the chronotypes (F=2,257; df=2/67; ns), though NIR post hoc test indicated that women from intermediate group undertake more health behaviours than women classified as evening types (p<0,05). With respect to the group of men, there was a significant difference (ANOVA) between chronotypes in the mean HBQ scores (F=3,652; df=2/53; p<0,033). Group of men having an morning-type preference undertake more health behaviours (post-hoc NIR) compared to those with intermediate and evening disposition (p<0,05). Tabel 13 illustrates comparisons of mean MEQ and HBQ scores received by subjects from different age groups. TABEL 13. Mean MEQ and HBQ scores in three age groups (standard deviations in parentheses) Age groups N 19-34 N 35-49 N >50 51,43* 60,60* 65,93* MEQ (8,40) (7,29) (6,96) HBQ 39 28,02 (6,47) 40 29,17 (8,19) 43 30,65 (7,09) The present study supports the reported trend for increasing morningness with age. Mean MEQ and HBQ score was the lowest in 19-34 age group and the highest in those aged 50 and over. However, only average MEQ scores increased significantly (ANOVA) with age (F=38,361; df=2/121; p<0,000). There were no significant differences in mean HBQ scores by age (F=1,339; df=2/121; ns).

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