The Effects of Animal Assisted Therapy on Communication (PDF)

The Effects of Animal Assisted Therapy on Communication and Social Skills: A Meta-Analysis VICTOR CHITIC 1 ALINA S. RUSU 2 STEFAN SZAMOSKOZI 3 Abstract A meta-analysis was conducted to determine the efectiveness of Animal Assisted Therapy procedures (AAT) on the communication and social skills of several categories of individuals. The inclusion criteria for the articles were: (1) to be published in English, (2) to cover the AAT domain, (3) to utilize a control group, and (4) to offer enough data to allow the calculation of the effect size (d Cohen’s) of the AAT interventions on the social and communication skills. Four studies met the selection criteria. A large effect size was found for the effects of AAT programs on improving the communication and social skills of individuals participating to the studies. Also, several variables moderating the effects of AAT were identified, such as: the type of animal used and its level of training, the method of therapy administration (i.e., individual, group or mixed), the type of measurement and the number and duration of the sessions. Further research is needed to clarify the functional mechanisms of AAT. However, the current meta- analysis indicates that AAT might function as a complementary therapy in the treatment of communication and social skills defficits. Keywords AAT, animal assisted therapy, communication, social skills, meta-analysis 1. Doctoral School “Evidence-based Assessment and Psychological Interventions”, Babes- Bolyai University, Romania; email: [email protected] 2. Department of Clinical Psychology and Psychotherapy, Babes-Bolyai University, Romania; email: [email protected] 3. Department of Applied Psychology, Babes-Bolyai University, Romania; email: [email protected]  2 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI Introduction The practice of Animal Assisted Therapy (AAT) started in England in the late 18th century (at the York Asylum), although it was not recognised as a certified practice at that time (Chandler, 2005). In 1962, the American psychologist Boris Levinson was the first credited with the official usage of a dog in therapy, in clinical context (Chandler, 2005; Fine, 2000). Delta Society (www.deltasociety.org), one of the largest organisations responsible with the certification of man-dog therapy teams in the United States and several European countries, includes AAT in a broader spectrum of Animal Assisted Interventions, as it follows (from Standards of Practice for Animal- Assisted Activities and Therapy; www.deltasociety.org): (1) Animal Assisted Therapy : “AAT is a goal-directed intervention in which an animal that meets specific criteria is an integral part of the treatment process. AAT is directed and/or delivered by a health/human service pro- fessional with specialized expertise, and within the scope of practice of his/her profession. AAT is designed to promote improvement in human physical, social, emotional, and/or cognitive functioning /cognitive func- tioning refers to thinking and intellectual skills". The key factors include specified goals and objectives for each individual and a measurement of the progress of the animal-assisted intervention (2) Animal Assisted Activities: "AAA provides opportunities for motivational, educational, recreational, and/or therapeutic benefits to enhance quality of life. AAA are delivered in a variety of environments by specially trained pro- fessionals, paraprofessionals, and/or volunteers, in association with ani- mals that meet specific criteria". The key factors include the absence of spe- cific treatment goals, the volunteers and treatment providers are not re- quired to take detailed notes; the content of the visit is spontaneous and vis- its last as long or as short as needed. (3) Animal Assisted Education (AAE): is a goal directed intervention with an animal, aiming to educate the beneficiary on certain aspects. An example of such activities are reading stories in the presence of a dog, or reading stories to a dog (Prothmann, Bienert, & Ettrich, 2006; Grigore & Rusu, 2012). The most common therapy animals are dogs and horses (Chandler, 2005). Dogs can be easily trained and transported and, because of their pack instinct, they are willing to engage in interactions with humans. Horses, besides the psychological benefits they can bring to humans (i.e., lowering the stress level, increasing the self-esteem), can sucessfuly and less  The Effects of Animal Assisted Therapy on Communication and ... | 3 stressfuly replace certain physiotherapeutic exercises during the physical rehabilitation procedures. Due to the common usage of dogs and horses in AAT interventions (i.e., in USA, Canada, Australia and Western Europe), inclusion criteria and standardised procedures have been developed mainly for these two categories of animals (www.deltasociety.org). Regardless of the type of animal, when designing an AAT program, one has to consider the characteristics of the species, of the individual, the compatibility of the pacient with a specific animal, the therapeutic foundation of the interaction whith one particular animal, aspects related to animal welfare and, most importantly, the safety of the patient while interacting with the therapeutic animal (Chandler, 2005; Fine, 2000). The benefits of the human-animal interaction can be measured at physiological and psychological (cognitive, behavioral and emotional) levels. Until 2007, there were no published meta-analyses regarding the effects of TAA on the levels mentioned above. The year 2007 brings two important meta-analytical studies on the scientific investigation of AAT in general, and on depression, in particular. The meta-analysis of Souter and Miller (2007) specifies the positive impact of incorporating AAT in standardised therapeutic plans for depression, while the meta-analysis of Nimer and Lundhal (2007) indicates the effects of AAT in several domains, such as autistic disorders and quality of life of several categories of individuals, such as children, adollescents, adults and elderly people. Accounts regarding the benefits of AAT in the area of social and communication skills are numerous, yet few are supported by empirical data. In their meta-analysis conducted on 49 selected studies, Nimer and Lundahl (2007) report that the largest effect size of AAT was found in aleviating the effects of autism spectrum disorders (d=0.7), in which the main issue is related deficits in social and communication skills. Even though there have been a lot of attempts to define and conceptualise the social skills, the analysis of scietific literature indicates that there is no specific agreement when it comes to defining social skills. By integrating key concepts of several definitions, Merrell and Gimpel (1998) offer a comprehensive definition, suggesting that: “…social skills are learned, composed of specific behaviors, include initiations and responses, maximize social reinforcement, are interactive and situation-specific, and can be specified as targets for intervention.” This definition conceptualises social skills as adaptive behaviors, while the failure to use social skills is considered as a social skill deficit.  4 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI Gresham (1986) identifies three types of definitions related to social behavior in children. First type, the peer acceptance definitions, is based on the sociometric evaluation of the concept of peer acceptance, where children are encouraged to have a pro-social behavior if they are considered popular or accepted by peers (Gresham and Elliott, 1987; Rose-Krasnor, 1997). The second type is the category of behavioral definitions, which tries to explain social skills by using behavioral terms. Thus, social skills are considered behaviors specific to situations, more likely to be enforced and less likely to be punished (Gresham and Elliott, 1987). Behavioral definitions seem to have an advantage over peer acceptance definitions since specific antecedents, behaviors and consequences can be identified and adressed through treatment (Gresham and Elliott, 1987). The third type is the category of social validity-based definitions, which implies that social skills are defined as specifc behaviors with predictive rol in important social outcomes for children in certain situations (Gresham and Elliott, 1987). The important social outcomes include acceptance by others, school adjustment and psychological adjustment. Walter, Colvin and Ramsey (1995) add that social skills are behaviors that help the children to adapt to increasingly demanding social environments. Gresham and Elliott (1987) includes the social skills construct (which also incorporates the communication skills) within the social competence supra-construct, toghether with the construct of adaptive behaviors. Despite numerous attempts to conceptualise these constructs, they do not represent rigid categories; instead, they appear to be interwoven in complex relationships. An analysis of the scientific literature reveals several definitions of social skills (Elliott and Gresham, 1991; Sugai and Lewis, 1996). Most of these definitions concentrate on verbal and non-verbal behaviors (e.g., words, tone of voice, facial expressions, actions, body posture) used in interactions, and which result in positive social outcomes. Examples of specific social skills include (Elliott and Gresham, 1991; Sugai and Lewis, 1996): abilities related to peers/friends (greeting, listening, asking and answering questions, interrupting, initiation and maintaining of interactions), coping/survival skills (following rules and instructions, getting help, answering to peer pressure, negative feedback, expressing anger) and abilities related to problem solving and decision-making (identifying problems, setting objectives, generating and selecting alternatives, negotiation).  The Effects of Animal Assisted Therapy on Communication and ... | 5 Starting from the lack of a meta-analysis on the effects of AAT on the improvement of social and communicational skills, the present studies has to main objectives: 1. To analyse the effect size (computed based on Cohen’s d) from selected articles, in order to investigate the effectiveness of Animal Assisted Therapy in improving social and communication skills; 2. To identify the moderating variables and their effects on the specific outcomes (i.e., related to the social and communication skills) of AAT interventions. Method Seleciton of the articles The articles included in this study were selected from the following scientific databases: PubMed, PsychInfo and EBSCO. The key words used for identifying the articles were the following: animal assisted therapy, animal assisted intervention, pet facilitated intervention, pet therapy, pet psychoterapy, animal psychotherapy, animal assisted psychotherapy, dog assisted intervention, dog assisted therapy, animal assisted training, dog assisted training, animals+social, pet+social, animals+communication, pet+communication, AAT, AAT+social, AAT+communication. The next methodological step was to introduce the selection criteria for the articles that were found by using the keywords mentioned above. The following selection criteria were established in accordance with the objectives of the investigation and were based on the criteria suggested in the scientific literature: 1. The selected articles should cover only the AAT domain (articles reffering to animal aassisted activities or the benefits of companion animals; utility animals or robotic or plush surrogates were exclued). 2. The articles should to be published in English. 3. The articles should offer data about the improvement of social and communication skills through AAT, that should allow the authors to compute de effects size (e.g., mean values, standard deviation values, degrees of freedom, references of the statistical significance, descriptions of the statistical tests, the usage of a control group). Those studies with smal sample-size of the experimental and/or control  6 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI groups were not excluded from the analysis, as long as the authors offered enough data for computation of the effect size. A number of four articles meeting the selection criteria were included in the meta-analysis (see Fig. 1) Coding the articles The articles were coded for effect size and moderator variables, by using the software Comprehensive Meta-Analysis (Borenstein & Rothstein, 1999). The 13 encoded variables were later subjected to a moderation analysis, in order to determine the extent in which they moderate the effect of AAT on the social and communication skills. They were grouped in variable classes as follows (see Table 1): (1) variations in the characateristics of the subjects (three variables), (2) variations in the animals used (three variables), (3) variations in administration of the intervention (five variables), and (4) variations in the characteristics of the study (two variables). Potentially relevand studies initially identified (n=16026) Excluded studies, due to irrelevance (n=15994) Potentially adequate studies, selected for detailed examination (n=32) Studies included in the meta-analysis (n=4) Excluded studies, due to: ‐ Lack of control group ‐ Not referring to AAT ‐ Not containing data about the improve- ment of social and communication skills ‐ Insufficient data to allow computing of the effect size Figure 1. The QUORUM diagram of the selection of the articles which were included in the meta-analysis on the effects of AAT on the social and communication skills.  The Effects of Animal Assisted Therapy on Communication and ... | 7 (1) Variations in the characteristics of the subjects (three variables): The first variable coded was the age of the participant. Based on the Typical Models of Development (Broderick & Blewitt 2003), the age of the participants in the identified studies was distribuited in four cathegories: children (0-12), teenagers (13-17), adults (18-64), elders (>65). Where one of the experimental groups contained subjects from two age cathegories, the average age of the group was considered. The second coded variable was the level of cognitive integrity. The level of cognitive integrity was considered based on the information offered by studies investigating clinically healthy subjects, or subjects whose diagnosis did not include cognitive impairment, as well as by studies investigating subjects with various degrees of cognitive impairment (dementia, mental retardation. In the case of the study that did not specify whether the investigated subjects suffered or not of cognitive impairment (Barak et al., 2001), the information on the cognitive impairment was inferred based on the exclusion criteria of the subjects (e.g., diagnosis of chronic schizophrenia).The third coded variable was the number of subjects in each study. (2) Variations in the animals used (three variables): The first coded variable was the type of the animal used. From the four selected studies, two used dogs, one used a combination of dogs and cats (in unspecified proportion), and the forth study used another animal (i.e., dolphin). The second variable of interest was the AAT certification of the animal. An increasing number of organisations offering training and certification in AAT include clear selection criteria and standards for the animals used. For example, therapy dogs usually are tested for temperament, their behavior in certain conditions which are considered to simulate situations that may be encountered in therapy, and for the level training. If an animal was at least tested for one of the variables mentioned abobe, i.e., temperament, we coded it as being „certified”. The third coded variable within this category was the number of animals used in the therapy. (3) Variations in administration of the intervention (five variables): The first coded variable was the frequency of the session (daily or weekly). The second variable was the location in which the intervention took place: hospital, school or specialized AAT institution. In one study, the location was the Nuremberg Zoo, which developed a regular Dolphin Assisted Therapy program. A third coded variable was the manner of administration of the intervention (individual, group or mixed). The next two variables  8 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI reffered to the total number of sessions for each group and the duration of the session (in minutes). (4) Variations in the characteristics of the study (two variables): The two variables reffering to the characteristics of the study were the type of measurement (objective or subjective), and the treatment effect in time (follow-up). We considered that the authors measured medium term effects if the AAT effect was evaluated between 5 and 15 weeks after the intervention, and a long term effects if there was a follow-up interval longer than 15 weeks. Categorial Moderator Variables Moderator Variables Measured on a Continuous Scale Moderator Variable Number of Studies Moderator Variable Study Values Var. related to the subjects Age group Children 1 Number of subjects Barak et al., 2001 20 Adolescents 1 Banks and Banks, 2002 45 Elders 2 Breitenbach et al., 2009 94 Cognitive integrity Yes 2 Prothmann et al., 2006 100 No 2 Var. related to the animals Animal used Dogs 2 Number of animals used Barak et al., 2001 Dolphins 1 Banks and Banks, 2002 1 Dogs and cats (unspecified proportion) 1 Breitenbach et al., 2009 1 Animal certification Yes 3 Prothmann et al., 2006 4 No 1 Var. related to the intervention Session frequency Weekly 3 Number of sessions Barak et al., 2001 48 Daily 1 Banks and Banks 2002 6 Location of the sessions Hospital (or asylum) 3 Breitenbach et al., 2009 5 AAT specialized institution 1 Prothmann et al., 2006 5 Administration method Mixed 1 Duration of the sessions (in minutes) Barak et al., 2001 180 Individual 3 Banks and Banks, 2002 30  The Effects of Animal Assisted Therapy on Communication and ... | 9 Var. related to the study Type of measurement Objective 1 Breitenbach et. al. 2009 30 Subjective 3 Prothmann et al., 2006 30 Treatment effect in time Long 2 Medium 2 Tabel 1. Categorial and moderator variables identified in the meta- analysis Results The quantitative analysis of the efficiency of AAT interventions in the selected studies was based on the calculation of effect size (d, Cohen’s). A total of three articles allowed the direct calculation of the effect size based on the mean values and standard deviation, using Cohen’s formula (d) (Cohen, 1988). A free online calculator was used for calculation of d, which was available at http://web.uccs.edu/lbecker/Psy590/escalc3.htm. For the article that did not offer information about mean values and standard deviations (Banks and Banks, 2002), the eta squared indicator of effect size, which was obtained through covariance analysis, was converted to Cohen’s d. Table 2 shows the results of the quantitative analysis of the AAT articles. No Main Author Year No. of groups N Test used Dependent variables Effect size (d) 95% CI 1 Barak et al. 2001 2 20 Social Adaptative Functionng Evaluation (SAFE) Social- adaptative functioning 3,11 1,6 - 4,3 2 Banks and Banks 2002 3 45 UCLA Loneliness Scale (version 3) Feeling of loneliness 1,01 0,35 - 1,63 3 Breitenbach et al. 2009 3 94 Questionaire designed by the authors (Cronbach’s alpha =0.71-0.9) Communicatio n skills and social- emotional behavior 0,42 0,02 - 0,8 4 Prothmann et al. 2006 2 100 Basler Befindlichkeits- Skala Social extraversion 0,6 0,2 - 0,98 Tabel 2. Effect size values for the AAT intervention in the experimental group (comparation with the control group)  10 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI In order to assess whether the AAT intervention produced any effect on the dependent variable, the next step was to calculate a global effect size of all the studies (D), the variance of D (VARD) and the confidence interval (CI). The global effect size of all the sudies was D = 0.79. The effect size is considered to have a trivial value if the score is between 0 and 0.20, a small value if between 0.20 and 0.50, a medium value if between 0.5 and 0.8 and large value over 0.8. In our study, the effect of the AAT intervention on the investigated dependent variable (communication and social skills) is a large one. The variance of D (VARD) was 0.48, and the confidence interval for an alpha of 0.05 (95% CI) was 0.12 – 1.46. Considering that the confidence interval does not include 0 as a value, one can conclude that the result is statistically significant. Homogeneity was tested by using the Q test. A significant value of Q indicates that there are variations in the distribution of the effect size and thus implies a heterogenous model (Q =16.49, p = 0.001). The next step in the quantitative analysis of the data was a moderation analysis, aiming to investigate the role of the coded variables in moderating the effects of AAT on the dependent variable (see Table 3). The presence of statistical differences between the coded variables was examined by using the Qb test (Q between). A significant value of Qb indicates a significant moderation relationship. Moderator Variable Number of Studies Mean Effect Size Confidence Interval (95%) Qb Age group Children 1 0,42 (-2,334; 3,174) 1,045 p=0,593 Adolescents 1 0,6 (-2,154; 3,354) Elders 2 1,98 (-0,072; 4,032) Cognitive integrity Yes 2 0,797 (-0,476; 2,071) 0,543 p=0,461 No 2 1,5 (0,132; 2,869) Animal used Dogs 2 0,729 (0,356; 1,103) 14,336 p=0,001 Dolphins 1 0,42 (-0,031; 0,871) Dogs and cats (unspecified proportion) 1 3,11 (1,792; 4,428) Animal Yes 3 0,602 (0,318; 0,887) 13,324  The Effects of Animal Assisted Therapy on Communication and ... | 11 certification No 1 3,11 (1,794; 4,426) p=0,000 Session frequency Weekly 3 1,37 (0,353; 2,388) 0,944 p=0,331 Daily 1 0,42 (-1,205; 2,045) Location of the sessions Hospital (or asylum) 3 1,37 (0,353; 2,388) 0,944 p=0,331 AAT specialized institution 1 0,42 (-1,205; 2,045) Administration method Mixed 1 3,11 (1,794; 4,426) 13,324 p=0,000 Individual 3 0,602 (0,318; 0,887) Treatment effect in time Long 2 1,5 (0,132; 2,869) 0,543 p=0,461 Medium 2 0,797 (-0,476; 2,071) Type of measurement Objective 1 3,11 (1,794; 4,426) 13,324 p=0,000 Subjective 3 0,602 (0,318; 0,887) Tabel 3. The results of the analysis of the investigated categorial variables. The next step of the analysis was a linear regression designed to test the moderator variables measured on a continuous scale (see Table 4). Moderator Variable Regression Coefficient B Significance No. of subjects -0,017 0,0009 No. of animals used 0,005 0,285 No. of sessions 0,059 0,0009 Duration of the sessions (in minutes) 0,0168 0,0009 Tabel 4. The results of the analysis of the investigated continuous variables. The moderation analysis revealed the following variables that can play a part in moderating the effect of the AAT intervention on the improvement of communication and social skills: the type of animal used, the AAT certification of the animal, the manner of the administration of the AAT  12 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI intervention, the type of measurement, the number of subjects, the number of sessions, and the duration of the sessions. Finally, in order to determine the potential influence of the unpublished articles on this analysis, a „fail-safe N” or „file drawer” calculation (Rosenthal, 1979; Orwin, 1983; Lipsey and Wilson, 2001) was performed, which estimates the number of unpublished articles with non-significant results necesary to bring the global effect size of the articles analysed below the minimal accepted (in our case to 0.1). For the criterion of 0.1, the number of unpublished articles with a zero effect size should be 27. Conclusions and discussions The results of the current meta-analysis revealed a large effect size of the Animal Assisted Therapy interventions on the communication and social skills. Also, the data indicate the that the following variables can moderate the effects of AAT on improving the communication and social abilities: the type of animal used, the AAT certification of the animal, the manner of the administration of the AAT intervention, the type of measurement, the number of subjects, the number of sessions, and the duration of the sessions. Considering the results of this meta-analysis on the moderating effect of the animal used, the future studies should give more attention to this variable and they should include more accurate descriptions of the animals involved in the therapeutic process. In our investigations on the four studies that met the inclusion criteria, only one of the studies did offer this type of data (i.e., reffering to the breeds of dogs used). In one of the studies (Bank & Bank, 2002), no specification on the size of the dogs was given, even though the authors did offer information about the breeds (note: one dog was a terrier, but terriers can have a large size variations between different types). The size of the dog, especially if the investigated sample is comprised of children, may influence the decision of the participants to interact with the animal, or may impact the development of a relationship with the animal. If the animal is too large, the participants might experience anxiety related to the presence of the animal. Two of the studies using dogs reported that the animals were certified for AAT or at least they were oficially evaluated for their temperament (behavioral evaluation). No data on the AAT evaluators and the evaluation  The Effects of Animal Assisted Therapy on Communication and ... | 13 procedures were offered, as well on the behavioral standards the animal should meet. In one of the study, the authors specified that the dolphin was trained to response to several commands. None of the studies offered information on the temeperament of the animals. It is generally known that an excessively energetic dog for example, may worsen the simptoms of a child diagnosed with ADHD, while the same animal can act as a behavioral activator in relation with a person diagnosed with depression. Over the last decade, one can notice an increase in the scientific rigour of the AAT studies. Among the four studies included in our meta-analysis, the study of Breitenbach, Stumpf, Fersen & Ebert (2009) offers the most detailed description of the experimental procedure and of the measured variables; the aim of the study was to investigate the influence of the aquatic environment on the dependent variable (this is the study in which dolphins were used). Even though the authors did not find any statistically significant effects, it is important to note that the aquatic enviornment was taken into consideration as a potential moderator variable of the effects of AAT. Also, the authors tried to increase the construct validity of the research by considering non-specific effects as well, following an the analysis performed by Marino and Lilienfeld (2007) on the effects of dolphins- assisted therapy. One of the important non-specific effects in AAT that was not taken into consideration by any of the articles analysed in this meta-analysis is the novelty effect. The initial progress of the AAT intervention might be affected by the fact that the therapeutic animal can be percieved as a novel agent and, in some situations, it might generate positive affects, such as enthusiam, that could be apparently associated with the intervention. So, in the studies in which the short or medium term effects of AAT are measured, one should consider that there is a bias probability of the novelty of the situation. In one of the four studies (i.e., Prothmann, Bienert & Ettrich, 2006), the authors consider the probability that there are also other factors influencing the dependent variable, in the case of measuring the long-term effects of AAT. Due to the moderating variables pointed out by our meta-analysis, we consider that special attention should be given to them when designing AAT therapeutic plans. Moreover, the inclusion of more objective measurements in the research design will probably help in obtaining more accurate results and reduce the probability of different types of biases. The results of our meta-analysis support the positive effects of AAT procedures on specific  14 | VICTOR CHITIC; ALINA S. RUSU; STEFAN SZAMOSKOZI variables, such as communication and social skills, that are essential for the optimal functioning within a social environment for any human individual. Although there are already numerous studies investigating the global effects of AAT, there is a need for more research aimed at revealing specific effects of Animal Assisted Therapy.  The Effects of Animal Assisted Therapy on Communication and ... | 15 References BANKS, M.R. & BANKS, W.A. (2002). The Effects of Animal Assisted Therapy on Loneliness in an Elderly Population in Long Term Care Facilities. The Journals of Gerontology, 57, 428-432 BARAK, Y., SAVORAI, O., MAVASHEV, S. & BENI, A. (2001). Animal-assisted therapy for elderly schizophrenic patients: A one-year controlled trial. The American Journal of Geriatric Psychiatry, 9, 439-442 BORENSTEINA, HEDGES & ROTHSTEIN (2007). www.Meta-Analysis.com - accessed in 20.04.2012 BREITENBACH E., STUMPF E., FERSEN, L.V. & EBERT, H. (2009). Dolphin-Assisted Therapy: Changes in Interaction and Communication between Children with Severe Disabilities and Their Caregivers. Anthrozoos, 22, 277-289 BRODERICK, P. C. & BLEWITT, P. (2003). The Lifespan: Human Development for Helping Professionals. New Jersey: Merrill Prentice-Hall CHANDLER, K.C. (2005). Animal Assisted Therapy in Counseling. New York: Routledge COHEN, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Earlbaum Associates ELLIOTT, S. N., GRESHAM, F. M. & HEFFER, R. W. (1987). Social skills interventions. In C. A. Maher & J. Zins (Eds.), Psychoeducational interventions in schools (pp. 141-159). New York: Pergamon ELLIOTT, S. N. & GRESHAM, F. M. (1991). Social Skills intervention guide. Circle Pines, MN: American Guidance Service FINE, A. (2000). Handbook of animal-assisted therapy. NY: Academic Press GRESHAM, F. M. & ELLIOTT, S. N. (1984). Assessment and classification of children’s social skills: A review of methods and issues. School Psychology Review, 13, 292-301 GRESHAM, F. (1986). Conceptual and Definitional issues in the Assessment of Children's Social Skills: Implications for Classifications and Training. Journal of Clinical Child and Adolescent Psychology, 15, 3-15 GRESHAM F. M. & ELLIOTT, S.N. (1987). The relationship between adaptive behavior and social skills: issues in definition and assessment. The Journal for Special Education, 21, 167-181