Participants and procedure
To achieve the aim of this study, participants’ challenge and threat appraisals were assessed in anticipation of an experimentally administered mathematics stressor. These appraisals were then compared to participants’ stress mindsets. As the stressful mathematics task was completed after reporting on their appraisals, the stressor could not have harmed the participant, and as such, there was no need to address harm/loss appraisals. It was hypothesised that a more enhancing stress mindset would be positively associated with challenge appraisal, and negatively associated with threat appraisal. Power calculations using G*Power (version 3.1.9.2; Faul et al. 2014) estimated that a sample size of 160 participants was required to find a weak significant effect in a multiple regression with a type I error rate of .05 and power of .80. Power calculations were based on a weak effect as there is no research to suggest the expected effect size of this study and because weak effects produce larger sample size requirements.
Study participants were primarily recruited from a pool of undergraduate Psychology students at a university in Sydney, Australia. In total 99 students consented and participated in the study, in exchange for course credit. A further 38 participants were recruited through a snowballing process of community-based contacts of the researchers via social media to increase the total sample size closer to the required 160 to achieved adequate power to detect weak effects. Of these 38 participants, 13 provided consent but did not complete the survey. As such, 25 community-based participants were included in the final analysis. No incentives were offered to community-based participants. All participants were over the age of 18 and reported having no current psychological or stress-related disorders. Approval to conduct this research was granted by the institutional Human Research Ethics Committee.
This study was conducted entirely online, including the consent process. After reading study information and consent forms, participants completed the pre-manipulation questionnaire that assessed stress mindset, demographic characteristics, and a battery of covariate measures including lifetime stress, perceived stress, trait anxiety, and mathematics-related self-efficacy and anxiety, presented in random order. Participants then received instructions for a mathematics stressor task adapted from the Trier Social Stress Test (Kirschbaum et al. 1993). The original Trier Social Stress Test required participants to count backwards out loud from a four-digit number in steps of seven for a period of time. This was modified from the original task such that participants were required to type in their answers online for 10 subtractions (i.e., subtracting seven from 1955 ten times until the participant reached the number 1885). After reading their instructions, participants completed a post-manipulation stress mindset measure and a measure of primary appraisals (both presented in random order) before completing the mathematics task. Participants completed a second stress mindset measure to ensure that the stress mindset measure was not influenced by a stressful situation.
Measures
Stress mindset
The valid and reliable Stress Mindset Measure (Crum et al. 2013) was used to assess stress mindset. Participants indicated their agreement with eight phrases regarding their beliefs about stress, such as “the effects of stress are negative and should be avoided” on a 5-point Likert-type scale (0 “strongly disagree” to 4 “strongly agree”). Mean scores were calculated with a range from 0 to 4 with higher scores representing a greater stress-is-enhancing mindset (i.e., the stress mindset is informed strongly by positive beliefs) while lower scores represent a more debilitating mindset (i.e., the stress mindset is informed strongly by negative beliefs). Acceptable item reliability was achieved in the present study for both pre- (α = .85) and post- (α = .86) manipulation stress mindset.
Primary appraisal
Participants’ anticipatory challenge and threat appraisals of the mathematics task were assessed with a reliable and validated measure of cognitive appraisals by Skinner and Brewer (2002). Participants indicated their agreement with 16 statements addressing their thoughts about the mathematics task that they are about to complete, such as “I am focusing on the positive aspects of the mathematics task” (challenge appraisal), and “I worry that I will say or do the wrong thing in the mathematics task” (threat appraisal). Responses were rated on a 6-point Likert-type scale (1 “strongly disagree” to 6 “strongly agree”). Relevant items were averaged to produce total challenge, and total threat appraisal scores (Skinner and Brewer 2002), with higher scores representing a stronger appraisal for that subscale. Acceptable item reliability was achieved in the present study for both challenge (α = .88) and threat (α = .94) appraisal subscales.
Covariates
A number of stress-related factors were measured and controlled for in multivariate data analyses to reduce possible confounding.
Perceived stress
The Perceived Stress Scale (Cohen et al. 1983) is a reliable and validated measure of subjective stress. Participants indicated how often they felt or thought about each scenario described in 14 statements during the past month on a 5-point Likert-type scale (0 “never” to 4 “very often”). For example, “In the last month, how often have you been upset because of something that happened unexpectedly?” Scores were summed with higher scores representing greater perceived stress levels. Acceptable reliability was achieved in the present study for this scale (α = .73).
Lifetime stress
Experienced lifetime stress was assessed with the valid and reliable Life Event Inventory (Tennant and Andrews 1976). This scale is comprised of two subscales, Lifestyle Change (the magnitude of stressor-related change in the participant’s life) and Distress (the distressing quality of stressors). Participants endorsed any of the 66 stressors they had experienced (e.g., “Something you valued or cared for greatly was stolen or lost”). Each item had two weightings, one for each subscale. Weightings were summed where greater weightings represented greater distress or change. The current study demonstrated acceptable reliability for each subscale (α’s = .77).
Trait anxiety
The State-Trait Anxiety Inventory trait anxiety subscale (Spielberger et al. 1970) is a validated and reliable scale assessing an individual’s habitual, long-term anxiety (Langley et al. 2003). Responses reflect agreement with each of the 20 items (e.g., “I am a steady person”), rated on a 4-point Likert-type scale (1 “Not at all” to 4 “Very much”). Higher total scores represent greater trait anxiety. This study demonstrated acceptable item reliability for trait anxiety (α = .92).
General mathematics self-efficacy
Since a mathematics-based stressor was utilised in this study, mathematic self-efficacy was controlled for as it may influence how an individual responds to the mathematics stressor. Due to a lack of general mathematic specific self-efficacy measures, two related measures were adapted for general mathematics to ensure the proper control of mathematic self-efficacy.
Mathematics Self-Efficacy and Anxiety Questionnaire
This validated and reliable measure assessed self-efficacy and anxiety concerned with mathematics (May 2009). Items were originally written to be directed towards self-efficacy and anxiety in the mathematics of a calculus class. All items were adjusted to focus on general mathematics ability. The 16 items were on a 5-point Likert-type scale (1 “Never” to 5 “Usually”), such as “I believe I am the kind of person who is good at mathematics”. Items on each subscale were summed for total scores where higher scores represented greater mathematic self-efficacy and lower anxiety. Acceptable reliability was achieved in the present study for both self-efficacy (α = .96), and anxiety (α = .81).
Subjective Numeracy Scale
This reliable and valid scale was initially used to assess a medical patient’s understanding of ratios and odds (Fagerlin et al. 2007). Only the 4-item cognitive abilities section of this scale was used in the present study to assess beliefs in coping with certain mathematics tasks (e.g., “How good are you at working with fractions?”). Items were rated on a 6-point Likert-type scale (1 “Not at all good” to 6 “Extremely good”). Scores were summed to generate a total, higher scores represented greater mathematic self-efficacy. Acceptable reliability was achieved in the present study for subjective numeracy (α = .91).
Demographic characteristics
Participants provided information about their age, gender, marital status, their highest level of education, and place of residence.
Statistical analysis
Analyses were performed using SPSS statistical software, Version 22 (IBM 2013), with statistical significance set at p < .05 for the main analysis, and p < .10 for all analyses selecting covariates for the main analysis. Descriptive statistics were used to describe the obtained sample population. Chi square and t test analyses compared the two samples on all measures, and tested the mean difference between pre- and post-manipulation stress mindset to ensure that there was no significant difference these time points (i.e., to provide evidence that stress mindset is independent of the context of a stressor). Any differences between the two samples were controlled for in the main analyses. Pearson’s and Spearman’s correlations were used to assess for multicollinearity (defined as r or ρ ≥ 0.8), to check for characteristics related to the outcome variables (challenge appraisal and threat appraisal) that should be treated as covariates in subsequent analyses, and to assess whether pre-manipulation stress mindset scores predicted post-manipulation stress mindset scores. The relationships between stress mindset and both challenge and threat appraisal were assessed with two separate multiple linear regression analyses, one regression for each appraisal scale, controlling for appropriate covariates.