Suffixing Bias: Research Shows Language-Specific Roots, Challenging Universal Cognitive Theories

Verbal language, a defining characteristic of human beings, facilitates complex thought, cultural transmission, and intergenerational connection. The suffixing bias, a compelling phenomenon within language studies, questions why most languages favor suffixes over prefixes for grammatical meanings like tense or number. Is this preference linked to general cognition, language-specific factors, or random chance? At its core, the suffixing bias describes the tendency to indicate grammatical information via suffixes (word endings) rather than prefixes (word beginnings). For instance, English marks plurality with '-s' (cats) and past tense with '-ed' (walked). Suffixing languages outnumber prefixing languages by an eight-to-one ratio (Dryer, 2013). Theories addressing this imbalance range from domain-general cognitive constraints to language-specific structural requirements. Hupp, Sloutsky, and Culicover (2009) suggest that humans process sequences varying at the end more effectively than those varying at the beginning. This implies our cognitive system is adapted to changes occurring at the end of a sequence, a principle that extends to language processing. Experiments with English speakers showed that sequences differing at the end were perceived as more similar to previously learned sequences than those differing at the beginning. This trend appeared across various stimuli, suggesting a general cognitive bias. Challenging this, Martin and Culbertson (2020) studied Kîîtharaka speakers, whose Bantu language strongly favors prefixes (e.g., '-ntû,' person; 'muntû,' "one person"; 'antû,' "more than one person/people"). Participants judged the similarity of sequences (syllables or shapes), comparing a target sequence with versions altered at the beginning or end. Unlike English speakers, Kîîtharaka speakers preferred sequences differing at the beginning, aligning with their native language structure. This indicates that linguistic experience significantly affects cognitive biases, suggesting the suffixing preference may not be universal. A recent study by Ordin (2025) provides evidence that the suffixing bias is language-specific. The study used a statistical learning paradigm, a method for examining how humans extract patterns from continuous streams of stimuli. Participants included Spanish monolinguals (a strongly suffixing language) and Basque-Spanish bilinguals (Basque uses both suffixes and prefixes). Participants were exposed to streams of artificial words with embedded suffixes or prefixes. After familiarization, they completed tests assessing their ability to recognize these sequences. Spanish monolinguals demonstrated a strong suffixing bias, favoring suffixed artificial words. Basque bilinguals, exposed to both affix types in Basque, showed no preference and learned prefixed words better than Spanish monolinguals. This suggests that balanced exposure to prefixes and suffixes can neutralize the suffixing preference. Participants also performed similar tasks with non-linguistic sound stimuli. Neither group showed any preference for suffixing or prefixing in this context, reinforcing the idea that the suffixing preference is rooted in language-specific mechanisms rather than general cognitive processes. Ordin's study indicates that the suffixing bias is limited to linguistic material and influenced by native language morphology. This supports a language-specific origin for the bias and highlights the adaptability of human cognition to different language structures. The suffixing bias underscores the complex relationship between cognition, language, and culture, demonstrating how individual linguistic systems and socio-cultural contexts shape human language processing.