INTRODUCTION

The tendency to behave according to delayed consequences -what is commonly called self-control- is learned and consists specifically in the choice of the most long term optimal alternative, in terms of quality and magnitude of reinforcement or avoidance of the aversive stimulation (^{American Psychological Association, 2012}; ^{Martin & Pearl, 2006}; ^{Montgomery, 2008}, Skinner, 1974 quoted by ^{Gómez & Luciano, 1991}; ^{Theler And Shefrin, 1981}).

A report published by ^{American Psychology Association (2012)} mentions that self-control is related to healthy lifestyles, such as practicing a regular exercise routine, eating a healthy diet, evidence of high academic performance, lower rates of substance abuse and greater financial security, among others. In addition, reference is made to a variety of socially relevant issues, that are associated with the opposite trend: behavior according to immediate consequences, even if it involves experiencing unpleasant situations in the future these include obesity (^{American Psychology Association, 2012}; World Health Organization, 2012); cigarette smoking (World Health Organization & Ministry of Health, 2006); illicit drugs (United Nations, 2012; Tibbetts & Whittimore, 2002 cited by ^{Cáceres, Salazar, Varela & Tovar, 2006}); internet overuse related to the decrease of time allocated to academic behavior and work activities (^{García, 2008}); and environmental pollution (^{Corral, 2006}; World Health Organization, 2010).

The relevance of this variable has led different authors to propose strategies that favor development of self-controlled behaviors. Initially, Skinner (1974, cited by ^{Montgomery, 2008}) referred to the following procedures: 1) restriction and physical help; 2) manipulation of states of deprivation and satiety; 3) manipulation of emotional states; 4) use of aversive stimuli; 5) use of drugs or stimulants; 6) self-reinforcement or self-extinguishment; 7) self-punishment of undesirable responses and 8) incompatible responses.

Subsequently, different investigations have come to differentiate three useful procedures to increase the probability of choosing a delayed option in a situation of choice. The first one is called maximization of response by manipulation of delay interval, which has to do with the manipulation of quantity, quality or retardation of reinforcement (^{Dixon & Cummings, 2001}; ^{Gómez & Luciano, 1991}, 2000). With the application of this procedure it has been found that the closer the end of the waiting interval, the greater the probabilities of waiting (^{González, Ávila, Juárez & Miranda, 2011}). Similarly, it has been observed that it is possible to increase self-control by means of choice tests repetitions, increasing progressively the delay to obtain reinforcement of greater magnitude (^{Dixon & Cummings, 2001}).

The second procedure is the use of distractors or alternative behaviors, which proposes that distractors of immediate reinforcers or attention to other stimuli facilitate waiting (^{Dixon, Rehfeldt & Randich, 2003}; ^{Gómez & Luciano, 1991}). In other words, the probability of choosing the delayed reinforcer option increases when there is the possibility of performing simultaneous alternating activities at the time of waiting (^{Dixon & Cummings, 2001}; ^{Grosch & Neuringer, 1981}).

The third process relates to the formulation of self-instructions, self-reinforcement, or its joint application (O'Leary & Duvey, 1979 cited by ^{Gómez & Luciano, 1991}). Within this latter category are the programs of correspondence say-do, in which the participant is trained to show consistency between the description of what he will do and what he actually does after verbally saying it; in these procedures, no aid such as models or waiting instructions is required (^{Gómez and Luciano, 2000}).

In relation to these procedures, ^{Gómez and Luciano (1991}) observed that with the gradual increase of delay, even though increasing the choice of the delayed reinforcer of greater magnitude in the trained situation, transfer of untrained behaviors is not achieved. Unlike this, the say-do procedure, not only generates a waiting repertoire, but also produces a repertoire of facilitation (equivalent to the dis-tractors).In the same way, they observed that a functional generalization of the say-do procedure can be given through the similarity of instructions or contextual -or specific- characteristics of one task to another.

This last group of procedures to generate self-controlled behavior, reveals that language constitutes a relevant variable for the study of human self-control (^{Benabou & Tirole, 2004}; ^{Gómez, López & Mesa, 2007}; ^{Gómez & Luciano, 1991}, ²⁰⁰⁰; ^{Guevremont, Osnes & Stokes, 1986}, ^{Luciano, 1992}, ^{Montgomery, 2008}, ^{Wilson & Luciano, 2007}).

The interest in the study of language from a behavioral perspective goes back to the first systematic approach of itself, made by ^{Skinner (1981}), who in addition to characterizing it as any behavior that is learned through reinforcement, raised the concept of "conditional discrimination "as an aspect of central importance for its understanding. This phenomenon refers to a situation in which the response of an individual to stimulus depends on others that alter the functions of the first (^{Alós, Guerrero, Falla & Amo, 2013}; ^{Hernández & Sandoval, 2003}). Conditional discrimination studies generated a relevant context for the discovery and conceptualization of a procedure for experimental analysis of category formation: the equivalence of stimuli (^{Sidman, 1971}; ^{Zentall, Galizio & Critchfield, 2002}).

The emergence of sorts of equivalent stimuli is a basic behavioral process that has spawned explained relational responses that arise without direct training, in other words, from their linking -mutual or combinatorial- with other stimulus (^{Hernández & Sandoval, 2003}). In the 1990s, an analytic-behavioral approach to language and cognition was proposed, which was called Relational Frame Theory (RFT) that addresses the emergence of relations between directly untrained stimuli and arbitrarily applicable relational responses through more general terminology, which is adapted not only to relations of equivalence, but also to those of non-equivalence (like opposition, distinction, comparison, temporality or causality, among other) (^{Barnes-Holmes, Rodríguez & Whelan, 2005}; ^{Hayes, Barnes-Holmes & Roche, 2001}).

From this perspective of RFT, language is an operant response that consists of learning to relate events with arbitrarily established criteria -not based on their formal properties-, through various examples and situations that lead to abstract the contextual key that relates them and apply it to different and original events (Valdivia & ^{Luciano, 2006}). Thus, the response of a participant to stimuli never seen before is presented as a function of contextual clues that delimits relationship frames, which can be of equivalence -is equal to-, of difference -is different from- of comparison -more than -less than-, of temporality -before - after- or of causality -"if ... then"-, among others, which define the relationship between events (^{Hayes et al., 2001}; ^{Luciano, Gómez, Hernández & Cabello, 2001}).

From this perspective, the description of a contingency affects the referred events, because of the possibility of transferring or transforming functions between stimuli -words and events referred to- that are part of a relational frame working function with relational frames to which they belong (^{Luciano et al., 2001}). In relation to self-control behavior, the acquisition of a consolidated verbal repertoire allows human beings, among other things, to functionally contact the appetitive properties of choice that lead to the delayed reinforcer or aversives associated with the immediate reinforcer's choice, even if they are not normally present in the situation they interact with.

According to ^{Wilson and Luciano (2007}), verbal control over an action in a particular context would be a case of arbitrary relationship between verbal and non-verbal behavior. According to the authors, such descriptions develop a discriminative control when in the history of the individual, numerous and varied interactions have been generated to form pertinent relational frames. In this way, the interactions that an individual has -since his childhood- with other speakers are determinants for verbal regulation repertoire.

In the case of choice behavior under the self-control paradigm, verbal behavior allows contact consequences that will only be available long term -or that are unlikely-through verbal linkage of the current situation with events that are not present in the same spatial-temporal dimension; in addition, it facilitates the learning of behaviors without the need to be exposed to aversive consequences (^{Törneke, Luciano & Valdivia, 2008}).

Evidence of this phenomenon is illustrated in the study by ^{Binder, Dixon and Ghezzi (2000}) conducted with children between the ages of 3 and 5 who had been diagnosed with attention disorder and hyperactivity. Specifically, the results showed that when the participants were initially proposed the option between an immediate reinforcer of lesser magnitude and a delayed reinforcer of greater magnitude, all chose the reinforcer of lesser magnitude, however when slight delays were introduced to obtain a greater magnitude reinforcer along with the verbalization of the self-rule "If I wait more, I will have the biggest", all the participants demonstrated self-control. In this same line, ^{Ruiz and Gómez (2016}), in a study carried out with people between the ages of 12 and 15, observed that as they learn to respond to different verbalizations, the frequency of behaviors increases in function of delayed consequences, which turn out to be indispensable in situations where they should focus on monotonous tasks that do not represent an immediate reward, but which will be useful in the future.

Based on the above, this work was carried out under the hypothesis that correspondence -or absence of it- between descriptions of contingencies and contingencies mediated by other individuals during infancy, affects adjustment before descriptions of contingencies that involve behavior on function of delayed consequences of greater magnitude, in other words, on self-controlled behavior. It is understood by correspondence between descriptions of contingencies and contingencies, when the verbalization of elements of the contingency to be experienced, coincides or is directly related to what the person actually experiences. On the other hand, it is understood that absence of correspondence is the inconsistency between the verbalization of the elements of the contingency and the experience itself.

METHOD

Two experiments were carried out to analyze the differential effect of a correspondence story or absence of correspondence between descriptions of contingencies and contingencies, on the choice of immediate or delayed reinforcers. The first was performed in a laboratory situation and the second in a simulated natural situation.

EXPERIMENT I

Design

In this study, an intrasubject design was used and participants were randomly assigned to two experimental conditions, as shown in Table 1.

Table 1 Experimental conditions 

After each block of tests, the self-control variable was measured by means of a task of choice. It is worth mentioning that the design used does not incorporate a baseline, since performing a previous measurement of choice behaviour could affect the subsequent evaluations given the learning effects (^{Kerlinger & Lee, 2002}).

RESULTS

The results of the experiment indicate that the choice of participants between a delayed reinforcer of greater magnitude and an immediate reinforcer of lesser magnitude is affected after experiencing correspondence or lack of correspondence between the descriptions of contingencies provided and the contingencies they describe.

Among the six participants who initially experienced the absence correspondence and correspondence blocks, three chose the smallest immediate reinforcer in the first situation (P2, P3 and P6) and the other three chose to transcribe the 500 letters to obtain the reinforcer delay of greater magnitude (P1, P4 and P5). However, two of the participants who chose this last option (P1 and P4) left the activity within four minutes of the presentation of the first instigator, and only one participant completed the transcription of the letters (P5) after 28 minutes.

When passing to the blocks of correspondence between descriptions of contingencies and contingencies, one of the participants chose the immediate reinforce of lesser magnitude (P2) and five participants chose the delayed reinforcer of greater magnitude (P1, P3, P4, P5 and P6). Of the latter participants, three (P4, P5, and P6) completed the task in an average of 30.4 minutes, despite the presentation of the instigators, one wrote more than half of the content, leaving the task at 16 minutes of execution (P1), and another participant left the activity after 4 minutes (P3). Figure 1 shows the number of letters transcribed by the participants in each block.

Figure 1 Choice behavior in the experimental condition of absent correspondence and correspondence. 

On the other hand, the six participants who first experienced the correspondence blocks and subsequently the absence of correspondence blocks, chose the delayed rein-forcer in the first block; five completed letter transcriptions in approximately 30 minutes (P7, P9, P10, P11 and P12) and one performed more than half of the transcription (P8), leaving the task 15 minutes after the start of the execution (before the presentation of the fourth instigator).

Afterwards, in the absent correspondence blocks, four participants chose the immediate reinforcer (P8, P9, P11 and P12) and two opted for the delayed reinforcer of greater magnitude (P7 and P10); One of them managed to finish the task after 24 minutes (P10) and the other gave up 4 minutes after the first instigator. Figure 2 shows the number of letters transcribed by the participants in each block of this experimental condition.

Figure 2 Choice behavior in the experimental condition of correspondence and absent correspondence. 

In summary, it is possible to observe that when the participants underwent correspondence trials between descriptions of contingencies and contingencies, prior to the situation of choice under a self-control paradigm showed a greater tendency to choose the delayed reinforcer of greater magnitude, that is, to show self-controlled behavior. In contrast, in the absence of correspondence trials, the participants showed a greater tendency to choose the immediate reinforcer of smaller magnitude. This effect was observed in the measurement of the two experimental conditions.

EXPERIMENT II

Design

In this experiment, an intrasubject design applied in a simulated natural situation was used. Table 2 presents the experimental conditions.

Table 2 Experimental conditions Experimental conditions 

Subsequently to each block of tests, the self-control variable was evaluated by means of a task of choice.

RESULTS

The results of this experiment indicated that the behavior of choice in the self-control evaluation of 23 of the 37 participants who experienced the trials in the following order: correspondence - absent correspondence, was modified as a function of each block. When correspondence was presented between contingency and contingency descriptions, the participants chose to perform a monotonous task in order to obtain a deferred reinforcer of greater magnitude. On the contrary, when they experienced absence of correspondence in the previous experimental situation, they behaved according to immediate consequences.

In the same sequence of presentation of the blocks, 13 participants maintained their behavior in the two measurements of self-control; 12 of them behaved according to delayed consequences after each block of trials, and one according to immediate consequences in both measurements.

In the same situation, a participant showed a behavior under a paradigm of self-control contrary to expectations, i.e., after experiencing correspondence between descriptions and contingencies, in the task of self-control the participant chose the immediate option. On the other hand, when the participants experienced no correspondence, he/she behaved according to delayed consequences in the self-control evaluation

Figure 3 shows the trend of choice during the self-assessment of the 37 participants previously described.

Figure 3 Choice behavior in the experimental condition of correspondence and absent correspondence. 

On the other hand, the results indicated that the behavior of choice during the self-control evaluation of 27 of the 36 participants who experienced the sequence of absent correspondence and correspondence was modified as a function of themselves.

In other words, in the absence of correspondence between the description of contingencies and consequences, they chose the immediate option, however during session two, when correspondence was presented between the description given by the experimenter and the contingencies, these participants chose the delayed option during the configured task to evaluate self-control. Of the remaining participants, seven chose the delayed option in the two self-monitoring assessments and one maintained their choice behavior in the immediate option.

Finally, one participant behaved in a way that was contrary to expectations, that is, when he experienced absence of correspondence between descriptions and contingencies, he chose the delayed option, and changed his choice to the immediate option in session two in which he experienced correspondence between descriptions and contingencies. The results described above are shown in Figure 4.

Figure 4 Choice behavior in the experimental condition absent correspondence and correspondence. 

DISCUSSION

In the two experiments carried out, the participants were exposed to correspondence and non-correspondence trials between contingency and contingency descriptions, and subsequently underwent a choice task under a self-control paradigm that had no formal or functional similarity to the above-mentioned trials; in others words, the choice of delayed or immediate reinforcer was not directly trained.

It was observed that after experiencing correspondence trials between contingency and contingency descriptions, the participants of the study mostly chose the largest delayed enhancer, which in light of the TRF might imply that they responded to an event (situation of choice) in terms of another (correspondence tests), by abstracting the function of a contextual key of causality present in the two situations (^{Msetfi, Wade & Murphy, 2013}, ^{Törneke et al., 2008}, Valdivia & ^{Luciano, 2006}). In other words, it could be assumed that the description of the contingency that configured the situation of choice to measure self-control included contextual keys (if ... then) that allowed the participant to frame their behavior and environmental events, in causal relationships, which made it possible for their behavior to be controlled by consequences that would probably only be experienced in the long term.

In this way, the learning history established during the exposure to correspondence tests altered the functions of contingency descriptions, increasing their effectiveness to link the delayed consequence with the task that would allow it to be contacted (^{Gómez et al., 2007}).

This finding is supported by ^{Barnes-Holmes et al. (2005}), who mention that relational learning is a flexible operant response that is not detached from consequence control. In fact, before being able to behave in the face of an event in function of another, the repetition of multiple copies that allow to abstract the function of the key that relates them are necessary, which is still modifiable by experience.

In contrast, it could be said that after experiencing a history of absence of correspondence between descriptions of contingencies and contingencies, relational responding was weakened, preventing the contextual key contained in the description from effectively controlling choice behavior. That is, the learning history generated in this situation affected the effectiveness of the description of contingencies to alter its referred events causing the majority of participants to avoid performing a long and monotonous task (transcription of letters), even though when the description that constituted the situation of choice was the condition to obtain a reinforcer of greater magnitude. As a result, other present conditions (immediate reinforcement) became more relevant in the choice behavior of the participants (^{Gómez et al., 2007}; ^{Gómez & Luciano, 2000}).

These results are related to findings from previous studies which have shown that providing real contingency descriptions and continuously reinforcing the behavioural adjustment of individuals to contingency descriptions favors the participant's effectiveness in conditional discrimination tasks. On the contrary, the falsity of the descriptions, in addition to generating variability in the executions, progressively decreases the follow-up of contingency descriptions and increases the probability of behaving under the control of contingencies (^{Martínez, Ortíz & González, 2007}; ^{Ortíz, González, Rosas & Alcaraz, 2006}).

However, although the tendency to choose one or another reinforcer according to the experimented trials was evidenced in the majority of participants, some exceptions were presented. In the first experiment, two participants chose the delayed reinforcer in the self-assessment evaluation independently from the correspondence trials experienced (correspondence or absence of correspondence between contingency and contingency descriptions), and another maintained the choice of immediate reinforcer. In the second experiment, 21 of the 73 participants maintained their behavior in the two self-monitoring measures after the two types of trials, 19 in the delayed option and two in the immediate option. This behavior - which was not the general trend - suggests that the pre-experimental history of the participants (a variable that was not under the control of the investigators), could have interacted with the experimental conditions, so that the functions acquired were not already altered by the contextual key "Yes ... then".

Considering that relational learning is a functionally generalized operant (^{Gómez et al., 2007}), it can be inferred from these results that by fostering a history of correspondence through varied situations and sources during the development of an individual, (^{Ruiz & Gómez, 2010}), it is possible to strengthen the function of contextual keys that facilitate the tracking of contingency descriptions and allow them to be under the control of their own verbal behaviour favoring the choice of delayed reinforcers of greater magnitude.

This is in line with the approaches of the Acceptance and Commitment Therapy, derived from the RFT, from which it is possible to postulate that the behavior of the participants was regulated through "pliance", a type of conduct governed by rule in which the function of a verbal formula is established by a history in which the consequences are mediated by others (^{Hayes et al., 2001}; ^{Wilson & Luciano, 2007}). In the same sense, the behavior of the participants who evidenced variability in choice behavior in the self-control task was facilitated by a "flexible pliance", as it allowed them to come into contact with the contingencies they experienced during the phases of correspondence and absence of correspondence between descriptions of contingencies and contingencies, which made their choice during the task of self-control adjusted according to the experimental history, in the delayed or immediate option.

In contrast, in cases where choice behavior was not presented in the expected direction, the possibility arises that this behavior may have occurred due to verbal regulation that can produce a "rigid pliance" which made it difficult for participants to get in touch with the contingencies of correspondence and absence of correspondence stories. In these cases, it is likely that behavior was regulated by verbal relationships that were previously established in the participant's learning history, relationships that were not altered by the experimental history. Authors such as Valdivia and ^{Luciano (2006}) explain this behavior by stating that words and gestures can alter the functions of events in different levels and forms, depending on personal history and the events that occur at a given moment.

By the above, and assuming from the point of view of TMR, the individual behaves in the present according to the functions learned directly and derived through their history (^{Luciano, Valdivia, Gutiérrez & Páez, 2006}). Based on these findings, we suggest the study of other individual factors involved in the behavior of choice under the self-control paradigm, as well as the development of research aimed at explaining the variability of behavior of individuals in situations where self-control is evident. For example, a person may be more inclined to adopt a healthy diet and perform an exercise routine, but spending much of their time watching television, rather than performing their school or work activities.

Likewise, this study can be replicated with participants of different ages in order to verify if the effect of the experimental variation of the history of correspondence between descriptions of contingencies and contingencies, the tendency to choose immediate or delayed consequences, varies in function of age taking into account that the verbal relationships that are established become more complex as they interact with novel situations or modify the already established language functions.

To conclude, it should be mentioned that these results are preliminary. Before taking them into the applied context, it is necessary to perform other experiments that confirm the functional relationship between language and self-control. It is worth noting that this publication shows the results of a study in a context where control mechanisms allow the isolation of foreign variables and increase the internal validity of the laboratory results (^{Kerlinger & Lee, 2002}) in a simulated natural environment, which, although increasing the probabilities of negatively affecting the internal validity, favors the external validity of the extracted conclusions. All of the above contribute significantly for purposes of science and in particular-contextualism: prediction and control of human behavior (Valdivia & ^{Luciano, 2006}).