The Relationship Between Moral Disengagement And Proactive Aggression And Its Brain Mechanism

Aggressive behavior is a common anti-social behavior in life,which brings a lot of harm to people's lives.Usually,according to the cause and external manifestation of the aggression behavior,the researchers divided the aggression behavior into proactive aggression and reactive aggression.The proactive aggression is an aggression initiated by an actor without being provoked by irritability and negative emotions.It is usually driven by instrumental motivation and is carried out after personal rational thinking and moral license.Its purpose is to obtain personal goals or benefits,whether the goal is related to material gain or social status.For example,robbery and school bullying and other behaviors that harm others for their own interests are all proactive aggressive behaviors.The research on proactive aggression will be of great significance to social stability and interpersonal harmony,and we will mainly explore this kind of aggressions.As an important influencing factor of proactive aggression,the level of individual moral disengagement is very important for the development of proactive aggression.Specifically,moral disengagement refers to individuals' certain cognitive tendencies,which include redefining their behaviors to make them looks like less harmful,and make the victims looks like less pain,and also minimizing their responsibilities in the harm behavioral consequences.The research on the relationship between moral disengagement and proactive aggression will help us to clarify the moral mechanism of the occurrence process of proactive aggression and provide a possible path in the moral field for reducing proactive aggression.However,most of the current studies on the relationship between moral disengagement and proactive aggression are limited to questionnaire measurement and lack the experimental method to verify the causal relationship between the two variables.This study will combine the characteristics of the two variables and use the pain-gain task to explore the causal relationship.At the same time,the brain mechanism of moral disengagement is still not clear,and exploring the brain mechanism and its relationship with proactive aggression will help us to intervene in moral disengagement and proactive aggression behavior.Therefore,in this study,we will use MRI technology to explore the brain mechanism of moral disengagement.Based on the pain-gain tasks and the characteristics of proactive aggression,we have adapted a new research paradigm to measure the level of proactive aggression and manipulate the level of moral disengagement.Based on the behavioral results of the study-experimental task,we conducted the fMRI experimental task,and conducted a preliminary investigation of the activation of the brain region during the moral disengagement process and its relationship with the proactive aggression behavior.In addition,we also pay attention to the relationship between trait moral disengagement and trait proactive aggression and the brain grey matter structure.Therefore,we further use the trait moral disengagement score to correlate with the gray matter structure of the brain as a whole brain,and establish a brain-moral-aggression model,which is a mediate model to explore possible relationships between the three variables.Based on the above research background,we plan to explore the following issues:(1)Whether individuals who have high level moral disengagement will conduct more proactive aggressive behaviors than those in the control group(study 1);(2)What the key brain regions of moral disengagement process and whether these brain regions can predict proactive aggressive behavior(study 2);what is the relationship between trait moral disengagement and brain gray matter structure? Does trait moral disengagement play a mediating role between brain gray matter structure and trait proactive aggression level(study 3)?Specifically,Study 1 explores the relationship between stateful moral disengagement and proactive aggression through the moral disengagement's pain-gain task.The study had 65 participants,including 20 males and 45 females,aged 18 to 25 years.In Study 1,different guidance was used to manipulate the participants' level of moral disengagement to explore its impact on proactive aggression.The t-test analysis results of independent samples showed that,after conducting moral reasoning guidance for individuals in the experimental group,their moral disengagement level was significantly higher than that of the control group,and the level of proactive aggression in the experimental group was also significantly higher than that of the control group.Study 2 used a similar research method as Study 1 to further validate the conclusions of Study 1,and used fMRI technology to explore the brain activation mechanism of individual moral disengagement process and its predictive effect on proactive aggression behavior.A total of 58 valid participants in Study 2(not repeated with participants in Study 1),including 23 males and 35 females,ranged in age from 19 to 23 years.In this study,the behavioral results were consistent with that in study 1.After moral disengagement guidance for individuals in the experimental group,the moral disengagement level was significantly higher than that of the control group,and the level of proactive aggression in the experimental group was also significantly higher than that of the control group.In addition,brain activation showed that the left dorsal medial prefrontal cortex was significantly activated in the process of moral disengagement.At the same time,this level of brain activation could Marginal significance predict the level of proactive aggression(r=0.371,p=0.057).Study 3 used the Proactive aggression Subscale and Bandura's Moral Disengagement Questionnaire to measure the two trait variables' levels of the participants,and take the trait moral disengagement score to correlate with the gray matter structure of the brain as a whole brain,and establish a brain-moral-aggression model.There were 280 participants in Study 3,including 123 males and 157 females,aged 17-33 years.The correlation analysis of whole-brain gray matter density showed that the moral disengagement level of the participants was positively correlated with the density of the left dorsal medial prefrontal lobe,and negatively correlated with the density of the left precuneus.In addition,moral disengagement level can completely mediate the relationship between the left dorsal medial prefrontal cortex and the level of proactive aggression.Combining the two studies,the following conclusions are drawn:(1)the behavior results of study 1 and study 2 show that the increase of moral disengagement level will increase the level of proactive aggression,and the causal relationship between the two is determined by the experimental method;(2)brain imaging results of study 2 and study 3 showed that the left dorsal medial prefrontal cortex was a key brain region for moral disengagement in both experimental and daily situations,and it could predict individual proactive aggressive behaviors by predicting moral disengagement behaviors.