of language. Studies have found that responding to an infant's babble with meaningless babble aids the infant's development; while the babble has no logical meaning, the verbal interaction demonstrates to the child the bidirectional nature of speech, and the importance of verbal feedback. Some experts advise that parents should not talk to young children solely in baby talk, but should integrate some normal adult speech as well. The high-pitched sound of CDS gives it special acoustic qualities which may appeal to the infant. CDS may aid a child in the acquisition and/or comprehension of language-particular rules which are otherwise unpredictable; an example is the reduction or avoidance of pronoun reversal errors. It has been also suggested that motherese is crucial for children to acquire the ability to ask questions. Use with non-infants The use of baby talk is not limited to interactions between adults and infants, as it may be used among adults, or by people to animals. In these instances, the outward style of the language may be that of baby talk, but is not considered actual "parentese", as it serves a different linguistic function (see pragmatics). Patronizing / derogatory baby talk Baby talk and imitations of it may be used by one non-infant to another as a form of verbal abuse, in which the talk is intended to infantilize the victim. This can occur during bullying, when the aggressor uses baby talk to assert that the victim is weak, cowardly, overemotional, or otherwise inferior. Flirtatious baby talk Baby talk may be used as a form of flirtation between sexual or romantic partners. In this instance, the baby talk may be an expression of tender intimacy, and may perhaps form part of affectionate sexual roleplaying in which one partner speaks and behaves childishly, while the other acts motherly or fatherly, responding in "parentese". One or both partners might perform the child role. Terms of endearment, such as poppet (or, indicatively, baby), may be used for the same purpose in communication between the partners. Baby talk with pets Many people speak to their dogs as if they were another human being. These actions are not providing communication with the dog, but social interactions for the speaker, usually in order to solve some problem. The speaking style people use when talking to dogs is very similar to CDL and has been referred to as Doggerel. People tend to use sentences of