Siblings or full siblings (["full"] "sisters" or "brothers") share the same biological parents. Full siblings are also the most common type of siblings. Twins are siblings that are born at the same time. Often, twins with a close relationship will develop a twin language from infanthood, a language only shared and understood between the two. Studies suggest that identical twins appear to display more twin talk than fraternal twins. At about 3 years of age, twin talk usually ends. Twins generally share a greater bond due to growing up together and being the same age.