The in-out effect: examining the role of perceptual fluency in the preference for words with inward-wandering consonantal articulation

Can sequencing of articulation ease explain the in-out effect? A preregistered test

Words whose consonantal articulation places move from the front of the mouth to the back (e.g. BADAKA; inward) receive more positive evaluations than words whose consonantal articulation places move from the back of the mouth to the front (e.g. KADABA; outward). This in-out effect has a variety of affective, cognitive, and even behavioural consequences, but its underlying mechanisms remain elusive. Most recently, a linguistic explanation has been proposed applying the linguistic easy-first account and the so-called labial-coronal effect from developmental speech research and phonology to the in-out effect: Labials (front) are easier to process than coronals (middle); and people prefer easy followed by harder motor components. Disentangling consonantal articulation direction and articulation place, the present three preregistered experiments (total N = 1012) found in-out effects for coronal-dorsal (back), and labial-dorsal articulation places. Critically, no in-out effect emerged for labial-coronal articulation places. Thus, the in-out effect is unlikely an instantiation of easy first.

On the emergence of the in-out effect across trials: two items do the trick

Individuals prefer letter strings whose consonantal articulation spots move from the front of the mouth to the back (e.g., BAKA, inward) over those with a reversed consonant order (e.g., KABA, outward), the so-called in-out effect. The present research explores whether individuals hold an internal standard or scheme of consonant order that triggers this effect. If this were the case, the in-out effect should already occur in one-trial between-subjects designs. If not, the in-out effect should emerge over the course of trials in within-subjects designs. In Experiments 1a-e (1b-e preregistered; total N = 2973; German, English, and Portuguese samples) employing a one-trial between-subjects design, no in-out effect was found. In Experiment 2 (N = 253), employing within-subjects designs with either 1, 5, 10, 30, or 50 trials per consonant order category (inward vs. outward), the in-out effect was absent in the first trial, but already surfaced for the first 2 trials, reached significance within the first 10 trials and a solid plateau within the first 20 trials. Of the four theoretical explanations, the present evidence favors the fluency/frequency and letter-position accounts and is at odds with the eating-related embodiment and easy-first accounts.

The In-Out Effect in the Perception and Production of Real Words

The in‐out effect refers to the tendency that novel words whose consonants follow an inward‐wandering pattern (e.g., P‐T‐K) are rated more positively than stimuli whose consonants follow an outward‐wandering pattern (e.g., K‐T‐P). While this effect appears to be reliable, it is not yet clear to what extent it generalizes to existing words in a language. In two large‐scale studies, we sought to extend the in‐out effect from pseudowords to real words and from perception to production. In Study 1, we investigated whether previously collected affective ratings for English and Dutch words were more positive for inward‐wandering words and more negative for outward‐wandering words. No systematic relationship between wandering direction and affective valence was found. In Study 2, we investigated whether inward‐wandering words are more likely to occur in positive online consumer restaurant reviews written in English and Dutch, compared to negative reviews, and whether this association was stronger for food ratings than for decor ratings. Again, no systematic relationship between wandering direction and review rating emerged. We suggest that the affective states triggered by different consonantal wandering directions might be used as a cue for forming judgments in the absence of other information, but that wandering direction is too low in salience to drive the shape of words in the lexicon.

What is preferred in the in-out effect: articulation locations or articulation movement direction?

Words whose consonant articulation locations move inward (from the front to the back of the mouth) are preferred over words with the opposite consonant articulation location direction, a phenomenon termed the in-out effect. Recently, an alternative explanation for the in-out effect has been proposed based on position-weighted consonant preferences instead of articulation location movement preferences. However, this explanation has only been tested with word fragments. In two experiments, we tested these explanations using both, word fragment and pseudo-word stimuli. For word fragments, preferences could be explained by position-weighted consonant preferences, while, for pseudo-words, stimuli containing articulation location movement were evaluated more favourably than stimuli not containing articulation location movement. Thus, the in-out effect for word stimuli depends on movement of articulation locations. This finding demonstrates that a word's sound symbolic meaning cannot always be explained by its individual letters but can depend on letter sequences.

The articulatory in-out effect: replicable, but inexplicable

People prefer inward over outward articulation dynamics, a phenomenon referred to as the articulatory in-out effect. It is empirically robust and generalizes across languages, settings, and stimuli. However, the theoretical explanation of the effect is still a matter of lively debate and in need of novel research directions.

When vowels make us smile: the influence of articulatory feedback in judgments of warmth and competence

In six studies (N=725), we extended the articulatory feedback hypothesis to person perception, examining how words featuring /i:/ sounds that activate the zygomaticus major muscle and words featuring /u:/ sounds activating the orbicularis oris muscle affect preference, warmth, and competence judgments of mock-usernames. Users with usernames including /i:/, in contrast to /u:/ sounds, were always preferred and judged as warmer and more competent. The impact of this manipulation in shaping preference as well as judgments on the core dimensions of social perception confirms the stability of the vowel-emotion link and the role of articulatory feedback in social information processing.

Oral Approach Avoidance

Words whose articulation resembles ingestion movements are preferred to words mimicking expectoration movements. This so-called in-out effect, suggesting that the oral movements caused by consonantal articulation automatically activate concordant motivational states, was already replicated in languages belonging to Germanic (e.g., German and English) and Italic (e.g., Portuguese) branches of the Indo-European family. However, it remains unknown whether such preference extends to the Indo-European branches whose writing system is based on the Cyrillic rather than Latin alphabet (e.g., Ukrainian), or whether it occurs in languages not belonging to the Indo-European family (e.g., Turkish). We replicated the in-out effect in two high-powered experiments (N = 274), with Ukrainian and Turkish native speakers, further supporting an embodied explanation for this intriguing preference.