Reciprocity - a state or relationship in which there is mutual action, influence, giving and taking, correspondence, etc., between two parties. 
The term reciprocity is derived from the Latin word, reciprocus, meaning alternating. Taking a closer look, reciprocus, is made up of the prefix re- , back, and pro, forward. These meanings imply a back and forth movement. The term, reciproque , similarly means "the natural return, the like, the reciprocal".  These basic definitions for the term reciprocity are related to other terms such as feedback, interactive, and causality.
According to the OED, feedback is "the return of a fraction of the output signal from one stage of a circuit to the input of the same or a preceding stage;" and "the modification, adjustment, or control of a process or system by result or effect of the process by a difference between a desired and actual result." For example, media breeds feedback. As the message is transmitted to the receiver, the media used as the transmitter results in feedback, either positive or negative feedback [see noise]. Jean Baudrillard comments on the nature of speech and how the reciprocity involved in face-to-face interaction is a result of their being a lack of a medium, thus yielding 100% feedback rather than just a fraction [see immediacy]. On the other hand, the term interactive also has two definitions meaning "reciprocally active and acting upon or influencing each other" and "pertaining to or being a computer or other electronic device that allows a two-way flow of information between it and a user, responding immediately to the latter's input."  For example, Spike Lee's film, Bamboozled, shows how essential the audience and television viewers are in their participation with the vaudeville show. Not only does the audience interact with the performers on stage through prompted clapping and cheering, but also the home viewers interact with the show in numerous ways.
The Hegel Dictionary defines reciprocity in relation to causality. Hegel's main argument is that cause and effect are inseparable. More specifically, "causality being the relation of action and reaction, or, more explicitly, of reciprocity, in which two or more substances interact in such a way that the states of the one are both the cause and effect of the states of the other"  This frame of thought can get a little confusing but by examining Kantian philosophy it can be explained further more. Kant defines reciprocity in terms of mutual action and reaction.  Furthermore, he states that, "substances perceived to co-exist in space stand in thoroughgoing community or mutual interaction or are in thoroughgoing reciprocity"  . The combining of the various definitions and terminology relating to the word reciprocity allows one to examine more closely its relation and meaning in the context of media.
Marshall McLuhan, Spike Lee, Jean Baudrillard, Enzenberger, Roman Jakobsen, and Umberto Eco are just a few 'media theorists' who comment on reciprocity in relation to the media. First, by examining McLuhan's stance, we learn that "the medium is the message". Secondly, he describes two different forms of media, the hot medium and the cool medium. A hot medium is considered to be high definition, low participation media containing lots of rapid information which is specialized and fragmented such as windows, photographs, and lectures.  A cool medium is a low definition, high participation, holistic slow medium such as television, cartoons, electricity, fishnet stockings, and seminars; they actively engage the audience. Of these two media, cool medium could be said to possess a reciprocity of the sender and receiver, the audience and the programmer. Hot medium does not reciprocate or involve the participation of a second party; rather, they are simply absorbing and taking in the media.
On a contradicting note, Enzensberger seems to state the opposite of McLuhan in terms of television and its involvement of a second party. The notion that television prevents communication and "allows no reciprocal action between the transmitter and receiver, technically speaking, it reduces feedback to the lowest point compatible with the system".  Enzensberger seems to consider television to be a hot medium according to McLuhan's definition while McLuhan classifies it as a cool medium. The level or participation and recipricality of television therefore is highly debatable.
In dealing with media as a form or communication and relaying messages, reciprocity plays an important role. Roman Jakobsen states "communication can always be reduced to the simple unity in which the two polar terms are mutually exclusive". By polar terms he is referring to the transmitter and the receiver and uses the following model to describe them:
Transmitter--Message--Receiver (Encoder--Message--Decoder) 
In dealing with reciprocity, the above model shows how "the two terms are artificially isolated and reunited by an objectified context called the message." 
In this model of communication, the reciprocity and antagonism of interlocutors are excluded. Baudrillard has some very specific notions with the idea of media and its lack of reciprocity. Specifically he quotes Roland Barthes in saying there is a non-reciprocity in literature, which subjects the reader to idleness, to being intransive by either accepting or rejecting the author's ideas. He also believes that "we live in an era of non-response-of irresponsibility, with minimal autonomous activity on the part of the spectator." 
Baudrillard also contradicts himself in his quoting of Enzensberger stating, "the media make possible the participation of the masses in a collective process that is social and socialized, participation which the practical means are in the hands of the masses themselves"  . This goes back to the example of the television. McLuhan classifies it as cool medium, with high participation, and high reciprocal effects. Some forms of communication such as speech are defined as "an exchange, as a reciprocal space of speech and a response and thus of a responsibility that is a personal, mutual correlation in exchange."  However, this definition of communication does not apply to all forms of media. According to Baudrillard, the mass media are anti-mediatory, intransive, and fabricate non-communication. Speech on the other hand must be able to "exchange, give and repay itself as is occasionally the case with looks and smiles". 
Umberto Eco's hypothesis basically states that the changing content of the message serves no purpose.  He sees the model of communication as a process of interaction between sender and receiver. This thought is further formulized by Baudrillard making the bold statement that "reciprocity comes into being through the destruction of mediums per se."  When there is no medium to transmit the message, there is total feedback, or complete reciprocity from the receiver, such as the example of speech used earlier. Whereas if there is a medium such as film, music, or painting, the receiver is forced to be more placid and absorbing of the art rather than an active participant in having a reciprocal relationship with the it.
According to Platonic philosophy especially in "The Allegory of the Cave," media has a way of removing the audience or bamboozling them. They often do not have active will power over what is shown or heard, but are left simply to absorb the art without any control over it. Baudrillard gives the prime example of the street being the alternate form of mass media. Speech or face-to-face interactions form reciprocal, antagonistic, and immediate reactions. Speech exchanged in a way functions as a dissolvement of media. It is important to realize communication as something other than the simple "transmission-reception of a message, it can also be considered reversible through feedback," therefore yielding a state of reciprocity between the transmitter and the receiver. 
Carla LynDale Carter