When communication is not only constituted by the words that make up sentences or when is totally devoid of them, it takes the name of metacommunication, which is the communication act performed with factors other than or additional to the spoken language. Because the transmission of messages takes place in a different way from the intrinsic meaning of the words or even without them, we speak of hierarchically superior communications, non-verbal messages, body language and behavioural communication.

The systemic-relational school of Palo Alto has also studied the analogical modalities through which communication takes place, that is all that concerns non-verbal language. Non-verbal communication takes place through three main modalities:

1. Paralinguistics: i.e. non-linguistic characteristics of speech: pronunciation, tone, dialectal inflection, speed, pauses, silence.
2. Kinesics: i.e. body movements, facial expressions and mimicry.
3.Proxemics i.e. proximity between interlocutors, which varies from culture to culture.

The proxemics varies according to the types of relationships between the interlocutors:

- Minimum distance (from 0 to 45 cm): characterizes intimate relationships;
- Personal distance (from 45 to 120 cm): close, but not excessively distant, allows the person to interact with the other by touching him/her;
- Social distance (from 120 to 360 cm): distance typical of work and school situations, often the distance and the difference in roles are marked by the juxtaposition of a barrier between the two interlocutors, such as a table or the chair;
- Public distance (over 360 cm): typical of theatres, concerts and courts.

The same word accompanied by specific tone or a body posture that is in contrast with the intrinsic message communicates something completely different from the meaning of the words used. These other elements therefore alter the meaning of the words being said, giving the communication a different meaning that prevails over them, so what will have value is not the set of phrases used but the body mimicry, the postural attitude, the tone of voice used. Starting from this assumption, Bateson, (1963) introduces the concepts of report and command, giving them two completely different meanings.

The report is the mere communication of a linguistic message, while the command is the communication of a metaphysical message, in fact it can take place even with just the use of glances or with a particular posture of the body without any word being expressed. Evaluating the communicative potential of metaphysics, one can come to the conclusion that it is the pathology of linguistic communication, in that it outclasses and replaces it, rendering it ineffective.

Human communication – the system of interacting and connecting with the outside world, in general or with a group of people in particular – can be functional, effective and therefore able to convey a message, in which case communication is a real balanced exchange of concepts, thoughts and ideas that enrich anyone, both those who express them and those who receive them. On the contrary, it is defined as pathological communication which is deficient in its inter-relational system, inadequate, or ineffective, and which does not create connection or an active and productive exchange, nor does it create a fair intellectual and communicative exchange.

Palo Alto scholars also analysed pathological communication contexts, in particular, Bateson et al. (1956) argued that dysfunctional and paradoxical family communication was involved in the genesis of schizophrenia. In particular, the authors theorized the concept of “double bind”, that is a message composed of two different stances, one opposite of the other, where, for example, the oral content is contradicted by non-verbal language. A double bind occurs when an individual experiences conflicting emotional, verbal or physical messages.

During the double bind, the communication recipient is paralyzed when faced with the message’s incongruity and therefore his reaction of not responding to the message will also result paradoxical and incongruent. Bateson et al. (1956) give the example of a mother who sees her son after having been hospitalized for a long time: the son tries to hug the mother, she stiffens causing him to withdraw and the mother then comments “you don’t have to be afraid to express your feelings”. In this sense, the message that the mother expresses verbally does not correspond to the message conveyed by her non-verbal behaviour. Thus, the child finds himself immersed in a contradiction that involves affection and rejection at the same time.

The effect of the double bind will lead the individual to be unable to discriminate between modes of communication and therefore to the inability to correctly interpret the message communicated to him/her. The double bind thus becomes a sort of unsolvable puzzle that leads the individual, unable to reach a resolution, to experience anxiety and fear and feel powerless and intimidated.