The results in relation to the Community Study

Several differences were apparent when the results of the Experimental Study were compared with those of the Community Study. In particular the participants in the Experimental Study seemed to have greater beliefs about the role of genes in obesity - the variable that the Experimental Study set out to manipulate. The most important comparisons to make were those between the Control (non-genetic facts) group and the Community Study to see if they were similar and therefore allow stronger conclusions to be drawn from the Experimental Study.

6.5.1 Beliefs about the geneticness and controllability of characteristics

The ratings of the seven characteristics by both Experimental Study groups and the Community Study are presented in Figure 3.3 on the next page. The ratings were similar between the Community Study and Control group.

FIGURE 3.3. The perceived contribution of genes to human characteristics according to Experimental study group and

Community study sub-sample

5.5 5 4.5 4 3.5

I I I 3

6.5.2 Specific beliefs about the role of genes and other causal beliefs in obesity

Comparisons with the obesity causal sub-scale data revealed differences between the Control group of the Experimental Study and the Community Study sample. These differences are presented in Table 3.42 below. A significant difference existed between beliefs in a genetic aetiology and psychological aetiology across the two samples.

TABLE 3.42. Differences in the rating of causal sub-scales between the Experimental Study Control group and the entire Community Study sample (n=327)

Control group Mean (SD)

Community Study

Mean (SD) t-test sig.

Genetic causation 1.20 (1.16) .40 (1.54) .00

Behavioural cause 1.15(1.10) 1.34(1.27) .34

Environmental cause .14(1.41) .34(1.29) .28

As.a result of these analyses I decided to investigate whether these differences could be linked to differences in the demographics of the samples. Looking at the demographics it was apparent that the Experimental Study participants were considerably younger than the majority of the participants in the Community sample. Also, as the participants in the Experimental Study were at university, almost all participants would have educational qualifications within two years that would be higher than the majority of the Community Study participants. To control for these differences a sub-sample of the Community Study was derived of participants aged less than 30 years of age who indicated that they had a degree qualification (n=45). This Community Study sub-sample was then used to compare against the responses of the Control group.

Differences between the Control group and the Community Study sub-sample on the obesity causal sub-scales are presented in Table 3.43 below and depicted graphically in Figure 3.4 on the next page.

TABLE 3.43. Differences in the rating of causal sub-scales between the Experimental Study Control group and Community Study respondents aged less than 30 years with a university degree (n=45)

Control group Mean (SD)

Community Study sub-sample

Mean (SD) t-test sig.

Genetic cause 1.20(1.16) 1.11 (1.10) .68

Behavioural cause 1.15(1.10) .99 (1.51) .52

Environmental cause .14(1.41) .59 (1.29) .09

FIGURE 3.4. Obesity causa! sub-scale scores according to Expérimentai study group and Community study sub-sampie

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Genetic Behavioural Environ mental Psychological

♦ Control - o — Intervention ■A- - - General <30y & Uni

Causal sub-scale

The analyses show that there was no significant difference in ratings of genes as a causal factor in obesity between the Control group and the younger and more educated respondents in the Community Study. There are also no differences in the ratings of the other causes of obesity between the two samples. This provides evidence that the difference between the entire Community Study and Control group of the Experimental Study in beliefs about the causes of obesity could be attributed to demographic differences.

6.5.3 Attributions about obesity

Responses to the attributional items by the Control group and Community Study sub­ sample are presented in Table 3.44 on the next page. The Control group rated obesity as significantly less stable over time and less modifiable with treatment.

TABLE 3.44. Attributions of locus of control, stability, modifiability and blame in the Experimental Study Control group and Community Study respondents aged less than 30 years with a university degree (n=45)

Control group Mean (SD)

Community Study sub-sample

Mean (SD) t-test sig. Obesity can be modified with treatment. 1.08 (1.33) 1.64 (.87) .02 The cause of obesity lies within the individual. .59 (1.75) .91 (1.59) .34 The obese person is to blame for their obesity. -.43 (1.79) -.67 (1.77) .49

Obesity is stable over time. -1.95 (.96) -.77 (1.44) .00

Responses to the controllability item and the BAOP scale by the Control group and Community Study sub-sample were investigated next (see Table 3.45 below). Ttiere was a significant difference between the two samples on the controllability item but not on the BAOP measure. On the single item, the Control group rated obesity as less under the control of the person. Therefore, the different ratings items on the controllability, modifiability and stability of obesity do not appear to be a product of differences in age and education between the samples.

TABLE 3.45. BAOP scores and attributions of controllability in the Experimental Study Control group and Community Study respondents aged less than 30 years with a university degree (n=45)

Community Study Control group sub-sample

Mean (SD) Mean (SD) t-test sig.

Obesity is under the person's control -.70 (1.63) .18(1.70) .01

BAOP score 18.81 (6.50) 18.88 (7.50) .96

6.5.4 Summary of differences

In sum, the responses given by the Control (non-genetic facts) group of the Experimental Study were only sometimes significantly different to those of a sub-sample of the Community Study matched for age and education. The only differences were on items concerned with the attributional dimensions of controllability, stability and modifiability of obesity. The Control group rated obesity as being less controllable, stable and modifiable than the Community Study sub-sample.

CHAPTER 4