Manipulating causal variables

3.4.1 Manipulating negative mood

Many techniques have been developed since the mid 1960s for inducing mood states in participants. The earliest of these was the Velten mood induction procedure (e.g. Kenealy, 1986; Velten Jr, 1968), which involves participants reading aloud sixty self-referent statements that progress from neutral to negative. Music (e.g. Pignatiello, Camp, & Rasar, 1986; Västfjäll, 2002), film (Schotte, Cools, & McNally, 1990; Weisenberg, Raz, & Hener, 1998), and vignettes (Mayer, Allen, & Beauregard, 1995) have also all been utilized successfully to induce mood states. Across mood induction procedures, it appears that the effects are stronger for inducing negative mood states compared to positive mood states (Westermann, Spies, Stahl, & Hesse, 1996), although film/story mood inductions, and those involving receiving a gift, appear to induce elation (Gerrards-Hesse, Spies, & Hesse, 1994). In a review of mood induction techniques, Gilet (2008) highlights the existence of simple procedures, which involve one mood induction technique, and combined procedures, involving the use of two or more mood induction techniques. Seemingly, mood induction procedures have an additive effect, with combined mood induction procedures resulting in larger effects than simple procedures.

There are two dominant methodological issues in inducing mood states. The first issue concerns whether mood states induced in the laboratory are representative of naturally occurring moods. Martin (1990) highlights that mood inductions can operate through three different components: cognition (via thought processes), somatic processes (via bodily sensations), and emotion (via the participant’s intention to feel a particular emotion). Some

mood induction procedures operate primarily through cognitive (e.g., threat of public speaking to induce anxiety), somatic (asking participants to pose particular facial expressions), or emotion (e.g., autobiographical recall tasks) channels, while some (e.g., self- statement and music) are argued to engage all three processes, which is likely to be more reflective of naturally occurring moods (Martin, 1990). Despite the difficulties in ascertaining whether mood induction procedures induce emotions of a similar quality to those that naturally occur, the alternatives to exploring the role of mood on thoughts and behaviours are also not fully satisfactory. These alternatives include examining individuals who have emotion-based disorders, such as studying depressive individuals as an approximation of negative mood, or testing individuals who are in naturally occurring mood states. The difficulty with both of these alternative approaches is that there are numerous confounds that can account for naturally occurring mood (e.g., medication, temperamental/state differences), which may also impact upon the dependent variables in question. Thus, despite the questions surrounding the representativeness of induced mood states, they allow a better control of extraneous variables and individual differences. The second issue relates to demand characteristics induced through mood induction procedures. Westermann et al. (1996) report that effect sizes for mood inductions measured by self-report are larger than those obtained through behavioural measurements, a fact that they argue demonstrates that there is an element of demand characteristics in the process of inducing moods. Nonetheless, given that the effects are still above zero in the behavioural measurement conditions, mood induction procedures do not solely operate through demand characteristics (Westermann, et al., 1996).

It is important that researchers using mood induction procedures attempt to minimize demand characteristics, while also being mindful that stimuli such as films and music can evoke very different emotional reactions in different people; some participants may find a sketch from Mr Bean hilarious, while others may find it annoying. A promising approach has been developed by Scott and Cervone (2002). They presented participants with vignettes, either about imagining their best friend becoming terminally unwell (sadness mood induction procedure), or imagining their bedroom furniture (neutral control). Participants listened to these vignettes, which lasted around five minutes, through headphones. Given that listening to a sad story in the context of a lab experiment could have alerted some participants to the purpose of the task, Scott and Cervone (2002) added a convincing cover story; participants were told that the experiment was about imagery, and that participants needed to engage with the imagery task before completing a mental imagery questionnaire, which the

participants were told would assess the content and quality of any mental images evoked by the scenario. The benefit of inducing negative mood states in this way is that it allows for a condition that controls for the impact of priming on the dependent variables. Scott and Cervone (2002) told participants in the priming condition that the task was about sentence completion. They then asked participants to complete a sentence rating task while listening to the same information as the individuals in the negative mood group, except the information was presented in the third person rather than first person. Given that priming is one possible explanation for how negative mood leads to increased worry perseveration, the vignette methodology used by Scott and Cervone (2002) was used in the experimental work undertaken in this thesis, to allow an exploration of whether priming is a valid explanation.

3.4.2 Manipulating Intolerance of uncertainty

A detailed discussion of IU and its perceived role in worry was provided in Chapter 1, but IU can be summarized as “the way in which an individual perceives information in uncertain situations and responds to this information with a set of cognitive, emotional and behavioral reactions” (Ladouceur, et al., 1998, p. 141). Ladouceur et al., (2000) conducted the first examination of whether IU could be manipulated in the lab, and what impact this had on worrying. Participants took part in a computerized roulette game. Each participant was required to bet on 15 consecutive trials, with a bet set at $2. All participants received $20 at the start of the roulette task, and the task was fixed so that all participants finished with a total of $14. Bets could be placed in one of three columns of 12 numbers that were either black or red. The experimenter explained the probabilities associated with each bet (1 in 2 for odd vs. even, 1 in 3 for bets placed on a column, and 1 in 36 for a single number). After explaining the rules, participants were told that in this task, they had to place their bets on columns (i.e. a 1 in 3 chance of winning the bet). In order to motivate the participants, they were told that $100 would be donated to charity if they finished with at least $20 at the end of the 15 trials. In the condition designed to increase IU, participants were told that their chances of winning were unacceptable, that previously people had been allowed to bet on colours (so the participants now had worse odds, 1 in 3, versus 1 in 2), and the experimenter commented that they were noticing that the odds of winning were much worse. In contrast, participants in the condition designed to decrease IU were told that previously participants had to place their bets on single numbers (so the participants now had better odds of 1 in 3 versus 1 in 36). The experimenter also emphasized that it was only a game, and that someone at some point would win, so the charity would receive the money eventually. Ladouceur et al.

(2000) report that this manipulation successfully created differences between the two conditions on measures of IU, with the group in the condition designed to raise IU having higher IU scores than the group in the condition designed to reduce IU. While this methodology shows it is possible to generate differences in IU using short laboratory manipulations, this study has been criticized for only measuring worry about the gambling task, and thus it is not clear if the manipulation would have an impact on issues outside the task (Deschenes, et al., 2010).

In an attempt to manipulate participants’ beliefs about uncertainty, Deschenes et al. (2010) presented participants with a PowerPoint lecture on problem-solving and either provided positive information about the benefits of uncertainty on problem-solving (designed to decrease IU beliefs), or negative information about the interference of uncertainty on problem-solving (designed to increase IU beliefs). Although Deschenes et al. (2010) did observe difference in IU post-manipulation, this procedure risks confounding problem-solving with IU. This is problematic given the role that PSC plays in worry (see Chapter 1).

A different methodology, which is free of the problems of specificity and confounds with problem-solving comes from Kelly (2009). The manipulation used four sets of two short stories. In one set, the character has high IU. In the other set, the character has low IU. For both sets, there is a male version and a female version. The scenarios are gender-congruent to ensure the participants can relate as fully as possible to the character and their gender-typical attitudes. In each of the scenarios, the character encounters an uncertain situation that has a potentially negative outcome. Participants were given ten minutes to read the stories and try to understand the motivations of the central character, paying attention to how the character responded to his/her challenge. Afterwards, participants were asked to “think of a situation in your own life where you aren’t sure whether the outcome will be good or bad” and to briefly describe the situation. After spending five minutes describing their own uncertain life event, participants received the following instructions “We want you to imagine that you are Sean [or Sarah] from the stories you have just read, and that you keep a journal about your thoughts and feelings about key issues and events in your life. Please take fifteen minutes to write a journal entry describing how you would feel if you were Sean [or Sarah] and were experiencing the situation you have just described above. Try to be as detailed as possible in describing how you (Sean [or Sarah]) would feel about the dilemma”. After the fifteen minutes had passed, participants were given five minutes to read the diary entry they had written with

an emphasis placed on understanding the feelings of the central character. Kelly (2009) found that this generated differences in IU levels between the two groups, with the group reading about the character with high IU demonstrating higher IU scores than the group who had read about the character with low IU tendencies. This method of IU manipulation was selected for the experimental work conducted in this thesis. Firstly, this method is superior to other methods used in the literature as it is less affected by specificity to a particular task, such as the gambling scenario used by Ladouceur et al. (1997). Rather, this task is applicable to any scenario of the participants’ choosing. Secondly, it is not confounded with problem-solving, which was a drawback of the Deschenes et al. (2010) information manipulation, which framed IU as helpful or unhelpful when solving problems.

3.4.3 Manipulating problem-solving confidence

There is a dearth of research involving changing an individual’s PSC. Heppner (1988) defines PSC as “self-assurance while engaging in problem-solving activities” (p. 1). Davey et al. (1996) is the only study (to the author’s awareness) to emerge from the worry literature that includes a manipulation of PSC, and as such, this method was employed in experiments conducted for this thesis. Davey et al. (1996) manipulated PSC by providing false feedback to participants about their performance on a series of problem-solving tasks. The tasks were taken from the Means-Ends Problem-Solving Test (MEPS; Platt & Spivack, 1975). The MEPS involves presenting participants with the beginning and end of a story and asking them to coherently solve how the protagonist in the scenario could get from the beginning to the end (i.e. complete the middle of the story). After each scenario was completed, the experimenter took the script away to be ‘marked’. Participants were presented with a short results paragraph, describing how problem-solving ability was assessed, the mean score for each subscale, and the participant’s score for that scenario. Participants who were in the condition designed to increase PSC were consistently told that they had scored higher than the mean score for their age and gender, whereas participants in the condition designed to decrease PSC were consistently told that they had scored lower than the mean score for their age and gender. Davey et al. (1996) found that this procedure resulted in a significant difference between the two conditions on a visual analogue scale measuring how confident the participants felt when they tackled some of the important problems in their lives. The manipulation did not affect feelings of control over the problem, or how readily individuals endorsed approaching problems. It is difficult to examine the reliability and validity of manipulating PSC, given that this is the only manipulation experiment. Even so, Davey et al.

(1996) demonstrate that it is possible to alter an individual’s self-reported confidence in their problem-solving ability through providing false feedback.