Can Fast and Slow Intelligence Be Differentiated?

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  2 test  When using the data derived from the within-item split…

2.3 Intelligence tests 2.4 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 (  2 &  3 )  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 analysis 3.5 Speed and accuracy within-item splitwithin-person split gg  ’ 2 gg  ’ 2 1 1 gg.767 gg.661 within-item splitwithin-person split gg  ’ 2 gg  ’ 2 1 1 gg.646 gg.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