Relationship between the Implicit Association Test and intergroup behavior: A meta-analysis.

Using data from 217 research reports (N = 36,071, compared to 3,471 and 5,433 in previous meta-analyses), this meta-analysis investigated the conceptual and methodological conditions under which Implicit Association Tests (IATs) measuring attitudes, stereotypes, and identity correlate with criterion measures of intergroup behavior. We found significant implicit-criterion correlations (ICCs) and explicit-criterion correlations (ECCs), with unique contributions of implicit (ß = .14) and explicit measures (ß = .11) revealed by structural equation modeling. ICCs were found to be highly heterogeneous, making moderator analyses necessary. Basic study features or conceptual variables did not account for any heterogeneity: Unlike explicit measures, implicit measures predicted for all target groups and types of behavior, and implicit, but not explicit, measures were equally associated with behaviors varying in controllability and conscious awareness. However, ICCs differed greatly by methodological features: Studies with a declared focus on ICCs, standard IATs rather than variants, high-polarity attributes, behaviors measured in a relative (two categories present) rather than absolute manner (single category present), and high implicit-criterion correspondence (k = 13) produced a mean ICC of r = .37. Studies scoring low on these variables (k = 6) produced an ICC of r = .02. Examination of methodological properties-a novelty of this meta-analysis-revealed that most studies were vastly underpowered and analytic strategies regularly ignored measurement error. Recommendations, along with online applications for calculating statistical power and internal consistency are provided to improve future studies on the implicit-criterion relationship. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Phase transfer catalysts drive diverse organic solvent solubility of single-walled carbon nanotubes helically wrapped by ionic, semiconducting polymers.

Use of phase transfer catalysts such as 18-crown-6 enables ionic, linear conjugated poly[2,6-{1,5-bis(3-propoxysulfonicacidsodiumsalt)}naphthylene]ethynylene (PNES) to efficiently disperse single-walled carbon nanotubes (SWNTs) in multiple organic solvents under standard ultrasonication methods. Steady-state electronic absorption spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM) reveal that these SWNT suspensions are composed almost exclusively of individualized tubes. High-resolution TEM and AFM data show that the interaction of PNES with SWNTs in both protic and aprotic organic solvents provides a self-assembled superstructure in which a PNES monolayer helically wraps the nanotube surface with periodic and constant morphology (observed helical pitch length = 10 ± 2 nm); time-dependent examination of these suspensions indicates that these structures persist in solution over periods that span at least several months. Pump-probe transient absorption spectroscopy reveals that the excited state lifetimes and exciton binding energies of these well-defined nanotube-semiconducting polymer hybrid structures remain unchanged relative to analogous benchmark data acquired previously for standard sodium dodecylsulfate (SDS)-SWNT suspensions, regardless of solvent. These results demonstrate that the use of phase transfer catalysts with ionic semiconducting polymers that helically wrap SWNTs provide well-defined structures that solubulize SWNTs in a wide range of organic solvents while preserving critical nanotube semiconducting and conducting properties.