Adult sibling relationships and media multiplexity theory

Sibling relationships are among the longest-lasting relationships in people’s lives. Information and Communication Technologies (ICTs), including voice calls, texting, and social media, help adult siblings keep in touch. The present study tests media multiplexity theory (MMT) in the context of adult sibling relationships. In the first study, a quota sample of American adults completed several name listing tasks to identify their most important relationship partners, ranging from 0 to 16 people, and 29% of participants listed at least one sibling. Multilevel modeling (MLM) results found that emotional closeness between siblings was positively associated with the frequency of phone calls and emails and negatively associated with the frequency of person-to-person media sharing. Showing mixed support for MMT, the number of ICTs used was negatively associated with emotional closeness, but the overall frequency of ICT use was positively associated with closeness. In the second study, a quota sample of American adults identified six of their closest friendships, and siblings constituted 2.9% of friends listed. MLM results found that the frequency of phone calls and text messages between siblings was positively associated with emotional closeness. The number of ICTs used was unrelated to emotional closeness, but the overall frequency of ICT use was positively associated with closeness, showing partial support for MMT. Both studies suggested that the frequency of communicating across ICTs was associated with greater life satisfaction, accounting for sibling closeness.