Behavior Change

I have been biting my fingernails for the better part of the last 18 years, ever since my older brother came home from school imitating a fellow student who was apparently a nail biter herself. Initially acquired by observational learning, the behavior became so ingrained that a decade would pass before I first achieved success with trying to stop. Since then, I have enjoyed several periods of extinction, most recently in 2013, but ultimately resurgence would occur following particularly stressful events, such as finals or sickness in my family. The primary motivation for changing this behavior is the social embarrassment associated with having bitten nails. At 25 years old, I am ready to put this childhood habit behind me.
A survey of academic literature on the topic of nail biting, known scientifically as onychophagia, reveals a notable failure to operationally define the behavior. However, one study done by A.R. Craig in 2010 did have a suitable definition that I adapted to better fit my own purposes. In the current study, I define nail biting as the insertion of any finger into the mouth where there is contact between the nail and teeth. A discrete instance of nail biting concludes when any one fingernail is removed from contact with the teeth for at least two seconds. An important distinction is that actual biting of the nail is not necessary. This expanded definition allows for behaviors such as tapping the teeth to be included because my previous experience has shown that placing a fingernail in contact with my teeth in any manner, although unintentional, can be an antecedent for nail biting.
This study employs a single-subject, simple-comparison design. Although a reversal design would have been better able to establish a functional relationship between the independent variable (treatment) and the dependent variable (nail biting behavior), it requires that the behavior revert back to its baseline level to determine effectiveness of the treatment. Since I did not want to revert back to nail biting in the course of this study, I was content to merely see whether there was some type of improvement. Further, I have found that if I am able to keep from biting my nails long enough to see nail growth, the improved appearance is reinforcing enough in itself to sustain long-term extinction.

Taking into account both my personal experience and research on the topic, I decided to use an aversive stimulus to decrease my nail biting behavior. I chose one article in particular that provides empirical evidence for the effectiveness of such a treatment. In a 1996 study by K. W. Allen (1996), forty-five participants of mixed gender and age were assigned to one of three groups: competing response, mild aversion, or self-monitoring. All subjects were to keep track of the number of times they felt the urge to or actually did bite their nails and each was given specific instructions depending on the group to which they were assigned. The competing response group was to make a fist with the 'offending' hand for three minutes any time they felt an urge to bite or engaged in biting, while the mild aversion group was told to apply a bitter nail polish twice a day. The self-monitoring group functioned as the control. Allen found that only the aversion group showed a significant increase in nail length, while the competing response group just failed to reach significance. Perhaps more importantly, the aversion group alone showed continued improvement at follow-up.
To track my behavior throughout the study I decided upon two measures that best represented the goals I ultimately wish to achieve, namely the elimination of nail biting behavior and improved appearance. The first is a simple rate of response measure whereby I recorded the frequency with which I engaged in nail biting over the course of each day. Using an iOS application called 'Tally Track,' I added one tally mark for each discrete instance of nail biting and totaled the responses for each day. My goal for this study was to decrease the rate of nail biting behavior to no more than once a day. The second measure was borrowed from a 1952 study by Malone and Massler who developed a scale for measuring the severity of fingernail biting in children (see Figure 1). Using the description and diagram as a guide, each fingernail is assessed individually and given a score from zero to three, then the 10 scores are added to obtain a total score. My goal was to score no higher than five by the end of my treatment phase.
I designed my study so that I would have a one week baseline period followed by three weeks of treatment. The rate of response measure was taken on each of the 29 days and the severity of nail biting index was assessed on Day 1, and then at each subsequent week of the study (Days 8, 15, 22, and 29). After the baseline phase, I coated my nails with a product called 'Mavala Stop', which is marketed as a transparent nail polish with a distinct bitter taste to discourage nail biting and thumb sucking. The key ingredient is denatonium benzoate which is the most bitter chemical compound known. The directions said to apply every other day but I found that once every third day was enough to keep the bitter taste.
The behavioral principle in support of my intervention was positive punishment because nail biting was followed by the presentation of the bitter-tasting, aversive stimulus which resulted in a decrease in the future likelihood of engaging in nail biting. The bitter nail polish acted as a primary punisher since a bad taste is innately punishing. It is also an extrinsic punisher because the bad taste is not an inherent aspect of nail biting, but rather nail biting behavior is followed by a separate event'bad taste'that serves to punish biting.
A potential problem with using bitter substance as punishment to eliminate nail biting is that the nail polish could function as a discriminative stimulus so that nail biting is only suppressed with the bitter taste is known to be present. However, since the bitter polish is clear, this is less of a concern than something more salient. Also, once I observe visible nail growth, the appearance takes over as a natural reinforcer making the contrived punisher almost unnecessary. A benefit of using punishment is that it tends to increase one's attention to the environment. In my case, the bitter taste is an intense interruption that allows me to consider the antecedents for my nail biting behavior, thereby helping to eliminate engaging in nail biting without even realizing it.
Although there are certain risks involved with using punishment to deter behavior, several factors made it effective in my situation. First, the punishment for nail biting was immediate because the bitter taste necessarily followed putting a finger in my mouth without having to rely on my recognition of the behavior to deliver a punisher. In a similar vein, punishment consistently followed each occurrence of the unwanted behavior. This consistency at the outset facilitates suppression which can later be sufficiently maintained by more intermittent punishment, meaning that I could go back to using the nail polish every once in a while to better maintain the effects. Lastly, the punishment was intense enough from the beginning to suppress the nail biting behavior thereby preventing me from adapting to the bitter taste.

The behavioral theory that best fits with my intervention is the Avoidance Theory of Punishment which holds that in carrying out a punishment procedure, an avoidance conditioning procedure is also taking place, wherein any behavior other than the target behavior is negatively reinforced by the absence of the aversive stimulus. This applies to my behavior in that while the bitter taste is a punisher for nail biting, any non-biting behavior is reinforced by withholding the bitter taste. Unfortunately, this wasn't entirely accurate in this case because behaviors such as eating popcorn were also punished because the bitter flavor was tasted any time my fingers came into close proximity to my mouth, even for an acceptable purpose.
My behavior pattern during the baseline assessment period involved several episodes of nail biting which typically concluded when there was little or no nail left to bite. I took note of when I was engaging in nail biting to determine possible antecedents for my behavior. As previously noted, I have always considered stress to be a causal factor and, since I had exams scheduled for the first and fifth days of my baseline period, I expected to see a related increase in the rate of nail biting. Surprisingly, I found that the days with the highest rate of nail biting were in fact two days after each exam (see Figure 2). While the Day 3 increase could have been due to nervous anticipation of the second exam, the same cannot be said of the increase on Day 7. This finding points to the presence of additional precipitating variables that I ought to identify and consider in the future management of my nail biting behavior.
For the rate of nail biting measure, I saw a drastic improvement from baseline to treatment periods (see Figure 2). During the baseline phase, the number of times I engaged in nail biting each day ranged from 6 to 17 times, with a mean of about 11 times per day. The rate dropped to a mean of less than once per day during the treatment period, with both a median and mode of 0. The rate of nail biting in the baseline period alone accounted for nearly 80% of the total instances recorded throughout this study. By the third week of treatment, I had surpassed my original goal of limiting instances of biting to once a day, and maintained complete suppression of the behavior for the remaining nine days of the study.
My results on the severity of nail biting index showed a similar pattern of improvement (see Figure 3). There was an increase in severity from the beginning to the conclusion of the baseline period which correlates with the high rate of nail biting behavior. Once the treatment phase began, though, there was a pattern of decline consistent with typical, uninhibited nail growth. I achieved my target score of 5 on the index sometime during the second week of treatment and obtained a score of 0 by the conclusion of my study. These results were also maintained at one week post-treatment.
I did have a momentary lapse in my plan which is reflected in the data for rate of nail biting (see Figure 2). On Day 19, there was a small rise in the target behavior to 3 instances of nail biting. The reason for this deviation is that, since I had been so successful, I became complacent and neglected to apply the bitter nail polish for a few days. Once I recognized the lack of punishment for nail biting behavior, I immediately reapplied the aversive stimulus and my pattern behavior returned to its post-baseline levels. This shows that the bitter nail polish has a high degree of stimulus control over nail biting. In addition, the target behavior has a low resistance to extinction, most likely due to having been maintained on a continuous schedule.
The greatest influence on the effectiveness of my intervention was the intensity of the aversive, punishing stimulus. After just a few tastes of the bitter substance, I was highly deterred from engaging in nail biting. This, coupled with the visible results of my efforts, became the impetus I needed to sustain behavior change.

Source: Essay UK -

Not what you're looking for?


About this resource

This Pyschology essay was submitted to us by a student in order to help you with your studies.


No ratings yet!

Word count:

This page has approximately words.



If you use part of this page in your own work, you need to provide a citation, as follows:

Essay UK, Behavior Change. Available from: <> [16-02-19].

More information:

If you are the original author of this content and no longer wish to have it published on our website then please click on the link below to request removal:

Essay and dissertation help