psychotools (version 0.2-0)

StereotypeThreat: Stereotype Threat in Dutch Differential Aptitude Test

Description

Cross-section data from Differential Aptitude Test (DAT) among Dutch highschool students, along with experimental conditions pertaining to stereotype threat.

Usage

data("StereotypeThreat")

source

Provided by Jelte M. Wicherts.

Details

The data are taken from Study 1 of Wicherts et al. (2005) and have been used to study stereotype threat on intelligence test performance among Dutch highschool students.

On average, Dutch minority students attain lower educational levels compared to Dutch majority students and studies have shown that minority students are often viewed as less smart/educated. Conversely, minorities often feel discriminated against in scholastic domains.

Wicherts et al. (2005) administered an intelligence test consisting of three subtests (for numerical ability, abstract reasoning, and verbal reasoning) and varied the amount of stereotype threat related to ethnic minorities by changing the presentation of the test. In the "threat" condition, the questions were declared to be part of an intelligence test and also an ethnicity questionnaire was conducted prior to the DAT. In the "control" condition, intelligence was not mentioned and no ethnicity questionnaire was conducted.

The variables numerical, abstract, and verbal can be used to assess ability/intelligence. And the vintelligence, vgrades, vprejudice, and gpa variables capture identification with the scholastic domain.

See Wicherts et al. (2005) for details.

References

Wicherts, J.M., Conor, V.D., Hessen, D.J. (2005). Stereotype Threat and Group Differences in Test Performance: A Question of Measurement Invariance. Journal of Personality and Social Psychology, 89(5), 696-716.

Examples

## Data: Load and include/order wrt group variable
data("StereotypeThreat", package = "psychotools")
StereotypeThreat <- transform(StereotypeThreat, group = interaction(ethnicity, condition))
StereotypeThreat <- StereotypeThreat[order(StereotypeThreat$group),]

## Exploratory analysis (Table 2, p. 703)
tab2 <- with(StereotypeThreat, rbind(
   "#"         = tapply(numerical, group, length),
   "Numerical" = tapply(numerical, group, mean),
   "" = tapply(numerical, group, sd),
   "Abstract " = tapply(abstract,  group, mean),
   "" = tapply(abstract,  group, sd),
   "Verbal   " = tapply(verbal,    group, mean),
   "" = tapply(verbal,    group, sd)))
round(tab2, digits = 2)

## Corresponding boxplots
plot(numerical ~ group, data = StereotypeThreat)
plot(abstract  ~ group, data = StereotypeThreat)
plot(verbal    ~ group, data = StereotypeThreat)

## MANOVA (p. 703)
m <- lm(cbind(numerical, abstract, verbal) ~ ethnicity * condition, data = StereotypeThreat)
anova(m, update(m, . ~ . - ethnicity:condition))
## corresponding univariate results
printCoefmat(t(sapply(summary(m),
  function(x) x$coefficients["ethnicityminority:conditionthreat", ])))

## MGCFA (Table 3, p. 704)
## can be replicated using package lavaan
## convenience function for multi-group CFA on this data
mgcfa <- function(model, ...) cfa(model, data = StereotypeThreat,
  group = "group", likelihood = "wishart", start = "simple", ...)
		 
## list of all 9 models
m <- vector("list", length = 9)
names(m) <- c("m2", "m2a", "m3", "m3a", "m4", "m5", "m5a", "m5b", "m6")

## Step 2: Fix loadings across groups
f <- 'ability =~ abstract + verbal + numerical'
m$m2 <- mgcfa(f, group.equal = "loadings")

## Step 2a: Free numerical loading in group 4 (minority.threat)
f <- 'ability =~ abstract + verbal + c(l1, l1, l1, l4) * numerical'
m$m2a <- mgcfa(f, group.equal = "loadings")

## Step 3: Fix variances across groups
m$m3 <- mgcfa(f, group.equal = c("loadings", "residuals"))

## Step 3a: Free numerical variance in group 4
f <- c(f, 'numerical ~~ c(e1, e1, e1, e4) * numerical')
m$m3a <- mgcfa(f, group.equal = c("loadings", "residuals"))

## Step 4: Fix latent variances within conditions
f <- c(f, 'ability ~~ c(vmaj, vmin, vmaj, vmin) * ability')
m$m4 <- mgcfa(f, group.equal = c("loadings", "residuals"))

## Step 5: Fix certain means, free others
f <- c(f, 'numerical ~ c(na1, na1, na1, na4) * 1')
m$m5 <- mgcfa(f, group.equal = c("loadings", "residuals", "intercepts"))

## Step 5a: Free ability mean in group majority.control
f <- c(f, 'abstract ~ c(ar1, ar2, ar2, ar2) * 1')
m$m5a <- mgcfa(f, group.equal = c("loadings", "residuals", "intercepts"))

## Step 5b: Free also ability mean in group minority.control
f <- c(f[1:4], 'abstract ~ c(ar1, ar2, ar3, ar3) * 1')
m$m5b <- mgcfa(f, group.equal = c("loadings", "residuals", "intercepts"))

## Step 6: Different latent mean structure
f <- c(f, 'ability ~  c(maj, min1, maj, min2) * 1 + c(NA, 0, NA, 0) * 1')
m$m6 <- mgcfa(f, group.equal = c("loadings", "residuals", "intercepts"))

## Extract measures of fit
tab <- t(sapply(m, fitMeasures, c("chisq", "df", "pvalue", "rmsea", "cfi")))
tab <- rbind("1" = c(0, 0, 1, 0, 1), tab)
tab <- cbind(tab,
  delta_chisq = c(NA, abs(diff(tab[, "chisq"]))),
  delta_df = c(NA, diff(tab[, "df"])))
tab <- cbind(tab, "pvalue2" = pchisq(tab[, "delta_chisq"],
  abs(tab[, "delta_df"]), lower.tail = FALSE))
tab <- tab[, c(2, 1, 3, 7, 6, 8, 4, 5)]
round(tab, digits = 3)