Regardless of the language spoken, prosodic features of speech (including variations in amplitude and rhythm) are important for conveying emotional states and semantic meanings. Such differences in prosodic structure can allow for monotone versus demonstrative speech. Previous research has shown that features of speech including prosody often converge when pairs of speakers interact. However, few studies have investigated how convergence applies to speakers in bilingual conversations, despite bilingualism being prevalent globally. For example, in lingua receptiva situations, each speaker uses a preferred language that the other understands. Further, prior studies have found convergence to be related to rapport and have theorized it to be important for successful communication, but few studies have analyzed how either prosody or prosodic convergence are correlated with various forms of performance. This dissertation aims to contribute a stronger understanding of how hierarchical temporal structure—a novel feature of prosody—and convergence between these structures correlate with performance, as well as monolingual and bilingual conversations (i.e., intra- and inter- language interactions).Chapter 1 introduces the background behind hierarchical temporal structure and the method of quantification. Likewise, the background and method of measurement are described for the convergence of hierarchical temporal structures, known as complexity matching. Chapter 2 then investigates how infant and adult prosody and volubility correlate with lexical development, as reported by the caregivers using a vocabulary assessment. Likewise, complexity matching and volubility matching were measured between infants and adults, and the relationship between both forms of convergence and vocabulary size is explored. Following this, Chapter 3 examines if either hierarchical temporal structure or speaking rate are related to collaborative task performance with adult pairs. Chapter 4 next tests if any differences for hierarchical temporal structure, complexity matching, or lexical matching were observed by language condition (Spanish only, English only, or one speaker used Spanish only and the other English only). Chapter 5 closes with a discussion of the implications and limitations of the findings, along with proposed future directions of study. This dissertation, Hierarchical Temporal Structure and Convergence in Development, Performance, and Bilingualism, is submitted by Sara Schneider in 2021 in partial fulfillment of the degree Doctor of Philosophy in Cognitive and Information Sciences at the University of California, Merced under the guidance of dissertation committee chair Chris Kello.