Previous studies suggested that pitch characteristics of lexical tones in Standard Chinese influence various sensory perceptions, but whether they iconically bias emotional experience remained unclear. We analyzed the arousal and valence ratings of bi-syllabic words in two corpora (Study 1) and conducted an affect rating experiment using a carefully designed corpus of bi-syllabic words (Study 2). Two-alternative forced-choice tasks further tested the robustness of lexical tones' affective iconicity in an auditory nonce word context (Study 3). Hierarchical linear models, generalized linear mixed models, and cross-validation were employed to understand the relationship between lexical tones and the emotional responses of tone-carrying words. Results consistently indicated that words with a falling-falling tonal sequence, both real and nonce words, received higher arousal ratings than those with rising-rising and rising-low tones. Only in nonce words, the high-high sequence was more likely to be associated with the low-arousal option; the falling-falling tone sequence was more often linked to negative-valence choice, while high-high and rising-rising tones with positive-valence. These findings, though subtle, suggest that the use of pitch in lexical tones influences emotional responses during the processing of tone-carrying words, pointing to an inherent iconic quality in lexical tones that may subtly shape speakers' emotional experiences.