Interacciones farmacológicas de la MDMA en humanos

First, relationships between the variables that compose the study’s motivational (non-change) resources are reported. Next, the relationship the personal character- istics variables (SES, gender, and prior achievement) had with one another and with motivational resources are described.

The correlational relationships between the non-change motivational re- sources variables

The correlational relationships found in study 1 and study 2 generally matched expectations. Four main results were anticipated: 1. The correlation between au- tonomous motives and perceived competence would be positive and small, with a value approximating to 0.25 (as suggested in Section 3.2.1). Furthermore, the cor- relational relationship would be stronger than that between controlled motives and perceived competence; 2. The correlation between autonomous and controlled mo- tives would be positive (as suggested in Section 3.2.2); 3. The correlation between autonomous motives and materialism would be small and negative (as suggested in Section 3.2.3). Furthermore, the correlational relationship between controlled motives and materialism would be small and positive; 4. The correlation between materialism and perceived competence would approximate to -0.24 (as suggested by Kasser et al., 2014 in Section 3.2.4).

Autonomous motives and perceived competence The first of these expec- tations, that autonomous motives and perceived competence would be positively correlated, was met in both studies and in all of the sets. In study 1, the correlation between autonomous motives and perceived competence was statistically significant,

6.1. Answering the research questions (RQs) 118

r = 0.34, p < 0.01, with a mean correlation across all eight sets equal to 0.323 in-

dicated (see Appendix, Table B.8). This approximated to the size of correlation suggested in Section 3.2.1. In comparison, in study 2 at Time 1, the relationship was not as strong as expected, where r = 0.18, ns. Similarly, at Time 2, the re- lationship was less strong too, where r = 0.22, ns. Sensitivity analysis indicated a mean correlation value of 0.17 at Time 1 (see Appendix, Table B.19), and 0.21 at Time 2 (see Appendix, Table B.29).

In summary, in both study 1 and 2 at Time 1 and Time 2 (and thus in all 24 sets of assumptions), the correlational relationship between autonomous motives and perceived competence was positive and non-marginal (i.e., greater than 0.1). Such a result is consistent with CET (Vansteenkiste, Niemiec, & Soenens (2010) and a key SDT theoretical assumption; namely, that competence will be accompanied by autonomy. Further support for this theoretical position came from the finding that in no set within the current study was controlled motives more strongly correlated with perceived competence than autonomous motives. In summary, the expected positive relationship between autonomous motives and perceived competence was found in study 1 and, to a lesser extent, in study 2.

Autonomous and controlled motives The second expectation, that controlled and autonomous motives would be positively correlated, was also met. In study 1, the correlation was medium-sized, where r = 0.36, p < 0.01 (see Table 5.4), with the relationship remaining statistically significant across all assumptions, and with a mean correlation value of 0.385 indicated (see Appendix, Table B.8). In comparison, in study 2 at Time 1, the correlation was large, where r = 0.52, p < 0.01 (see Table 5.11), with the relationship remaining statistically significant across all assumptions, and with a mean correlation value of 0.511 indicated (see Appendix, Table B.20). At Time 2, this correlation was somewhat stronger, where r = 0.65, p < 0.01 (see Table 5.12), with the relationship statistically significant across all the sets of assumptions and with a mean correlation value of 0.6 indicated (see Appendix, Table B.31). In other words, the correlation between these two variables was stronger in study 2 than study 1.

6.1. Answering the research questions (RQs) 119 In summary, although the direction of the correlation in both studies was as expected, the size of the correlation in study 2 was not. This finding is discussed further in Section 6.2.

Autonomous motives and materialism In Section 3.2.3, it was suggested that the relationship between autonomous motives and materialism would be negative and small. For instance, Black and Deci’s (2000) results showed that the correlation at Time 1 between RAI and grade orientation was r = -0.25, p < 0.01.

In the current study 1, the correlation between these two variables was statisti- cally significantly negative, where r = -0.28, p < 0.01 (see Table 5.4). Sensitivity analysis indicated that across all sets of assumptions, the relationship remained sta- tistically significantly negative (see Appendix, Table B.8). The mean correlation value indicated was -0.289. In comparison, controlled motives and materialism were only marginally (i.e., less than 0.1) and non-statistically significantly correlated.

In study 2 at Time 1, although the correlation was negative, it was smaller than expected, where r = -0.11, ns (see Table 5.11). In addition, sensitivity analysis indicated that across all sets of assumptions the relationship remained negative but small (and only marginal in three out of eight sets), with a mean correlation value of -0.1 indicated (see Appendix, Table B.21). Sensitivity analysis also indicated that controlled motives were positively correlated with materialism across all sets of assumptions, albeit the relationship was small, with a mean correlation value of 0.144 indicated (see Appendix, Table B.20).

However, the relationship between autonomous motives and materialism in study 2 at Time 2 became statistically significantly negative, where r = -0.36, p < 0.01 (see Table 5.11). Sensitivity analysis (see Appendix, Table B.31) indicated that the mean correlation value was -0.341. In six out of eight sets, the relationship remained statistically significantly negative at the p < 0.01 level. In comparison, controlled motives and materialism were negatively correlated at Time 2, but not statistically significantly so in any set (see Appendix, Table B.30). In addition, the size of the correlation was marginal, with sensitivity analysis indicating that the mean correlation value was -0.073.

6.1. Answering the research questions (RQs) 120 In summary, in both study 1 and study 2 materialism was negatively correlated with autonomous motives, often statistically significantly so. These findings gen- erally accord with SDT theorising, which posits that materialistic goals tend to be pursued for less autonomous reasons (Kasser et al., 2014).

Materialism and perceived competence The fourth expectation, that the cor- relation between materialism and perceived competence would be small and approx- imate to -0.24 (see Section 3.2.4) was met in study 1, but not at both times in study 2.

Specifically, in study 1, the correlation was r = -0.24, p < 0.01 (see Table 5.4). Sensitivity analysis indicated that across all sets materialism and perceived compe- tence were statistically significantly negatively correlated at the p < 0.01 level, with a mean correlation value of -0.27 indicated (see Appendix, Table B.10).

In study 2, the relationship between materialism and perceived competence was again negative. At Time 1, the relationship was similar to that in study 1 (see Table 5.11), where r = -0.19, ns, with a mean correlation value of -0.17 indicated (see Appendix, Table B.19). At Time 2, the variables were marginally correlated (i.e., less than 0.1). Hence no table is shown. According to SDT, individuals who are more focused on growth and development (as indicated by a negative score for the materialism variable) would be expected to experience a greater sense of personal competence compared to those who place relatively less importance on need-satisfying aspirations.

In summary, in study 1 the relationship between materialism and perceived com- petence showed the expected strength and direction. The expected direction was also shown in study 2, but only Time 1 showed (approximately) the expected size. The inter-relations between the personal characteristics variables and their relationship with the motivational resources variables

The inter-relations between the personal characteristics variables and their rela- tionship with the motivational resources variables were a mix of the expected and unexpected. The following section begins with prior performance before moving on

6.1. Answering the research questions (RQs) 121 to consider gender and SES.

Prior performance It was expected that better prior performance would accom- pany more positive competence perceptions, and lower prior performance would accompany lower competence perceptions (see Sections 2.4.1 and 3.2.5). In study 1, the relationship between GPA (English) and perceived competence was marginal (see Table 5.4 and Appendix, Table B.6). Also in study 1, the relationship between GPA (All) and perceived competence was small and non-statistically significant, with a mean correlation of 0.14 indicated (see Appendix, Table 5.4). Sensitivity analysis also indicated that prior performance, as GPA (All), was negatively corre- lated with materialism across all eight sets, with a mean correlation size of -0.195. The correlation was statistically significant in two out of eight sets (see Appendix, Table B.7).

In study 2, sensitivity analysis indicated that GPA (English) and perceived com- petence were not statistically significantly correlated at either Time 1 or 2 in any sets (see Appendix, Tables B.16 and B.26). Indeed, GPA (English) was no more than marginally correlated with all of the study’s motivational resources in study 2. In summary, prior performance, as GPA (English), was weakly and often only marginally correlated with motivational resources in both study 1 and 2. Perhaps most unexpectedly, this included perceived competence.

Gender As discussed in Section 3.2.6, it was expected that females would view their language courses more positively than males. Generally, however, this was not the case. For instance, in study 1, gender was not statistically significantly correlated with autonomous motives, controlled motives, or perceived competence. Indeed, correlations in study 1 between gender and these motivational resources did not rise above 0.1. The exception was materialism. In study 1, there was a statistically significant positive correlation between these two variables, r = 0.25,

p < 0.01, with males appearing to be more materialistic than females. Sensitivity

analysis showed that in six out of eight sets, this correlational relationship remained statistically significantly positive, with a mean correlation value of 0.234 indicated (see Appendix, Table B.2). Examination of the mean materialism scores for males

6.1. Answering the research questions (RQs) 122 and females in study 1 confirmed that females were less materialistic than males: the mean score for females was -0.96 (SD = 0.857), whereas for males it was - 0.46 (SD = 0.784). Mean difference effect size analysis indicated the difference in the average score for materialism for females and males in study 1 was associated with a medium effect size, where Hedges’ g = -0.60, 95 % CI [-0.24, -0.95]; that is, one that was found to exceed Cohen’s (1988) convention for a medium effect (d = 0.50). Also in study 1, gender and SES (Scaled) were statistically significantly correlated), where r = -0.22, p < 0.01 (see Table 5.4). Sensitivity analysis showed the relationship remained statistically significant across six out of eight sets, with a mean correlation value of -0.198 indicated (see Appendix, Table B.2). Finally, gender and GPA (English) were negatively, but only marginally, correlated.

Results in study 2 revealed that there were no statistically significant correlations between gender and perceived competence, materialism, or autonomous motives, which was unexpected (see Section 3.2.6). However, gender and controlled motives were statistically significantly negatively correlated in study 2 at Time 1, r = - 0.30, p < 0.01 across all the sets (see Appendix, Table B.13). The relationship became smaller and non-statistically significant at Time 2 (see Appendix, Table B.23). Contrary to expectations, therefore, there was some evidence to suggest females held less adaptive motivational resources in study 2 at Time 1.

Results in study 2 also revealed that gender and GPA (English) were negatively correlated (see Appendix, Table B.13), with sensitivity analysis indicating that the mean correlation value was -0.225. As discussed in Sections 2.4.3 and 3.3.4, large- scale studies have suggested that there is a gender gap in achievement, with females out-performing males and that the size of this gap may be small, where d = 0.21.

Gender and SES (Standardized and Weighted) were statistically significantly negatively correlated, where r = -0.38, p < 0.01. Sensitivity analysis indicated that the relationship remained statistically significantly correlated across all eight sets. The mean correlation value was r = -0.379. In addition, sensitivity analysis indi- cated the relationship between gender and SES (Scaled) was also negative (but not statistically significantly) in all the sets of assumptions, where the mean correlation value was -0.246 (see Appendix, Table B.13). Why gender was negatively correlated

6.1. Answering the research questions (RQs) 123 with SES in study 1 and 2 is puzzling. This question is returned to in Section 6.2.

In summary, results across both study 1 and 2 suggested that females held higher HSGPA scores and were from higher SES groups. Males were found to be more materialistic than females in study 1, but there was little evidence of this in study 2. In study 2 (Time 1), females appeared to endorse controlled motives more strongly than males, but there was little evidence of this in study 1, or in study 2 (Time 2). In other words, there was some evidence to suggest that females held more adaptive motivational resources than males, but there was also some to suggest the opposite. SES As indicated in Section 3.2.7, Butler’s (2015) results suggested a small cor- relation (of perhaps 0.22) between SES and autonomous motives would be found while others suggested no correlation. Sensitivity analysis indicated that in study 1, SES (both SE and SS) and autonomous motives were marginally correlated. Simi- larly, in study 2 at Time 1, sensitivity analysis indicated they were also marginally correlated. In study 2 at Time 2, SES (Scaled) and autonomous motives were unex- pectedly negatively correlated across all eight sets, with the mean correlation value of -0.133 indicated (see Appendix, Table B.28).

From the perspective that wealth affords potential educational advantages in the shape of greater access to better resources and less exposure to chronic stress (Will- ingham, 2012), it was expected that the correlations between perceived competence and SES would be statistically significantly positive and might approximate to 0.18 (see Section 3.2.8). This expectation, however, was only partially met. Specifically, only in study 1 was SES (Scaled) statistically significantly positively correlated with perceived competence, where r = 0.22, p < 0.01. Sensitivity analysis indicated that the relationship remained statistically significant in four out of eight sets, with a mean correlation value of 0.188 indicated (see Appendix, Table B.3). In study 2, the correlational relationship between SES (Standardized and Weighted) and perceived competence (Time 1) was small and non-statistically significant (see Ap- pendix, Table B.17), with a mean correlation value of -0.143 indicated. At Time 2, the relationship was marginal (see Appendix, Table B.26). SES (Scaled) was only marginally correlated with perceived competence at Time 1 and Time 2 (see

6.1. Answering the research questions (RQs) 124 Appendix, Tables B.18 and B.28). To investigate further potential differences in motivational patterns held by different SES groups in study 1 and 2, a series of median splits using the SES (Scaled) variable were conducted. This variable was chosen over the other SES variable, which was SES (SE) because regression analyses in both studies had demonstrated its importance in predicting academic outcomes. Performing a median split in study 1 on the SES (Scaled) variable (M = 2.01, SD = 0.254) to create a Low-SES (Scaled) group and a High-SES (Scaled) group revealed no statistically significant differences in motivational resources (i.e., autonomous motives, controlled motives, perceived competence, or materialism). Performing a median split with the SES (Scaled) variable (M = 2.3245, SD = 0.2868) in study 2 at both Time 1 and at Time 2 revealed no statistically significant difference in the non-change motivational resources variables between these Low and High SES groups. As for the motivational change variables, the SES (Scaled) median split revealed that none of the observed differences were statistically significant.

It was also expected that higher SES would be associated with higher prior per- formance, given students with higher SES would have access to better resources (see Section 3.3.1). However, in neither study 1 nor study 2 was SES (Scaled) sta- tistically significantly correlated with prior performance (remembering that neither IELTS scores nor GPA (All) were included in study 2). The direction was, however, positive in all sets.

In summary, there was limited evidence to suggest that different SES groups held distinctive patterns of motivational resources. Analysis in study 1 indicated that perceived competence and SES (Scaled) were statistically significantly positively correlated, but the size of the correlation was small and the result was not repeated in study 2. No other motivational variable was statistically significantly correlated with SES in either study. There was also little evidence that those in higher SES groups held more adaptive motives. Unexpectedly, in both studies only a weak relationship was found between SES and GPA (English). The GPA (English) score is examined in more detail later and more fully discussed in Section 6.2.

6.1. Answering the research questions (RQs) 125 RQ1: The overall pattern of results

Sensitivity analyses indicated that the correlations obtained using various sets of assumptions in a given study were generally similar in direction and size; hence the results obtained from the main data sets in each study can be considered reason- ably robust. Furthermore, correlation results between motivational resources across studies 1 and 2 were generally consistent with SDT-related theorizing.

Nevertheless, some less expected results did emerge. First, it was expected that females would hold more adaptive motivational resources than males. In study 1, this expectation was supported, but only for materialism: there was a statistically significant correlation between materialism and gender r = 0.25, p < 0.01, and mean difference effect size analysis indicated a statistically significant difference in materialism scores for males and females. There was little evidence that females held more adaptive aspirations in study 2. Furthermore, females in study 2 were found to have less adaptive motives at Time 1, albeit this was not apparent at Time 2. Second, it was expected that the relationship between competence perceptions and SES would be small but consistent. In study 1, there was a small, statistically significant correlation between perceived competence and SES, where r = 0.22, p < 0.01, but the relationship was only marginal in study 2 (at both Time 1 and 2). Third, it was expected that autonomous and controlled motives would be positively correlated, but the size of the correlation in study 2 was unexpectedly large. Fourth, correlational results across study 1 and 2 indicated that the relationships between the various personal characteristics variables were weaker than expected. For instance, GPA (English) and SES (Scaled) were weakly (almost marginally) correlated in both studies. Finally, aside from the relationship between autonomous and controlled motives, the pattern of results across study 1 and 2 indicated weaker correlations between the motivational resources in study 2 compared to study 1. Why this might have been so is returned to in Section 6.2.

6.1. Answering the research questions (RQs) 126