Can Fast and Slow Intelligence Be Differentiated?

8.4.2013

1. Introduction A popular present-day approach is to look for

pure measures of speed and power external to the test

Speed and power are different but positively correlated.

Slow responses are of a different nature than fast responses. Fast responses are based on more automatic

direct-link mediated processing while slow responses are based on repeating one's cognitive work and/or more controlled processing.

An interest in internal to the test

1.1 Fast and slow intelligence Different processes? Or different abilities? Qualitative process differences can be inferred

from the across-item pattern of difficulties, and qualitative ability differences from the across-person pattern of the latent trait values.

1.2 Aim of the study Time-homogeneity vs. time heterogeneity

Processes Abilities

Via two tasks: verbal analogy and matrices

1.3 Distinguishing between fast and slow responses Within-person split

For each person, a fast and a slow subset of items is determined.

Within-item split For each item, a fast and a slow subset of persons

in determined.

2.1 Model

2.2 Hypothesis testing 3P&3I vs 2P&3I, 3P&2I, and 2P&2I

AIC & BIC 3P&3I vs 3P&2I

LR test 3P&3I vs 2P&3I

Mixture c2 test When using the data derived from the within-

item split…

2.3 Intelligence tests2.4 Data sets Verbal analogies test

726 persons & 34 items Raven-like matrices test

503 persons & 35 items

3.1 Description of the data Response frequencies in two approaches Persons may differ more in their response

times than items do. Cronbach alpha: Fast responses were more

reliable than the slow responses.

3.2 Model comparison

Correlations between the two accuracy (q2 & q3)

Because the difficulties are fixed effects, no such correlations are available.

Estimated variances are larger for fast than slow

3.3 Correlations and variances

3.4 Additional analysis3.5 Speed and accuracy

within-item split within-person split

qg q’ 2 bg b’ 2

q1 -.184 .489 b1 .792 .736

qg .767 bg .661

within-item split within-person split

qg q’ 2 bg b’ 2

q1 -.422 -.965 b1 .630 .681

qg .646 bg .590

4. Discussion and conclusion Fast and slow intelligence can be differentiated, and

they are strongly correlated. Fast responses differentiate better than slow

responses between persons as well as items. A somewhat different kind of ability is measured for

respondents with primarily slow responses compared to the ability that is measured for respondents with primarily fast responses.

Given the higher variance of fast intelligence compared to slow intelligence, the ability of fast respondents is measured in a more reliable way than the ability of slow respondents.

Time pressure