Introduction

Personality is defined as the combination of characteristics or qualities that form an individual’s distinctive character. Everyone is considered to have a different and unique personality, based on personal experiences and different motivations and emotions. In the neuroscience world, personality has often been defined by a series of tests and examinations to boil down factors of personality. One of these tests is the Big-Five Personality test. This test is a valid test and confirmed through hundreds of papers as reliable. This personality test was coined by Meyers-Briggs in the early 1900s and identified five major factors of personality: openness, extroversion, conscientiousness, neuroticism and agreeableness (Shiota, 2018, chapter 13). All five of these factors have contributions to personality to help explain why one individual is similar or different from another. Throughout this paper, the link between these personality traits, particularly neuroticism, will be linked to a new phenomenon: social media addiction and its relation to amygdala activation. This paper will attempt to answer to the question, do neurotic individuals show higher amygdala activity and more addictive tendencies toward social media use?

To build an argument to answer this question, personality traits will first be linked to addictive tendencies. This will then build on the link between neuroticism and social media addiction to infer the amygdala activation in social media addicted users.

In this paper, the primary personality trait that will be explored is neuroticism. Neuroticism is a trait defined by the tendency towards higher levels of anxiety, depression, self-doubt and overall negative feelings around one’s self and the environment surrounding them. In general, those who are identified to have higher levels of neuroticism are  more susceptible to depression, anxiety and other debilitating mental illnesses and disabilities (Kanthamani, 1973). Those with higher levels of neuroticism are seen to be “unbalanced,” “unstable,” and in general a little more insecure and less confident in their abilities. With common interactions including self-blame for situations they are not responsible for, and insecure thoughts regarding their decisions, those with neuroticism are generally linked with feelings of “not feeling good enough,” “doubt in self or others around them,” or “insecurity in friendship and stability.” Neuroticism is determined based on a Likert scale and can range in severity and intensity (Shiota, 2018, chapter 13). The cause of neurotic tendencies is unknown and highly disputed between being caused by genetic or environmental factors.

Behavioral Basis of Neuroticism

As stated above, the cause of neurotic tendencies is highly debated. Some researchers argue that neuroticism is purely environmentally influenced, as in those with higher levels of neuroticism are linked to unhealthy family lives or discomfort in their current situation. However, other researchers believe that evidence suggests that neurotic tendencies could be caused by both environmental factors and genetic factors. Therefore, it can be assumed that neuroticism is a factor of personality that is fluid and can be influenced by both the actual genetic makeup of an organism in addition to the surrounding environment and influences. In accordance with this, researchers from the University of Glasgow found that neuroticism is linked with both genetic factors and social factors. The researchers at the University of Glasgow specifically linked neuroticism to 9 different genes within a large population of 100,00 participants from a variety of different databases. This research was originally intended to be utilized to provide treatment methods for those suffering with mental health and mental illnesses. The researchers of this study specifically noted, “neuroticism is an important risk factor for depression… hence, insights into the biological mechanisms underlying neuroticism may eventually be informative for the development of drugs to treat depression,” (Smith, 2016). By linking these genomes to different personality traits, personality was able to be studied from a genetic perspective to help identify patterns for treatment of different mental health disorders and discontinuities. 

Several different studies have been completed with the intention of linking back different genomes to personality traits. In a study by Nagel et al., participants allowed their DNA and genome data to be analyzed and linked back to neurological processes including specific activation in the brain amongst different kinds of neurons and genome loci. These studies found several overlapping genes and pathways linked to different aspects of personality, including those related to neuroticism as a personality trait. This study found enrichment in different brain regions and different cell types to be contributing factors that link back to neuroticism. Nagel et al. located the different loci of information to be targeted for mental health treatment (Nagel et al., 2018). The researchers found these overlapping loci to link these symptoms of negative feelings back to a genetic influence, implying that neurotic characteristics are largely genomic in nature. 

Although neurotic neuroticism is liked to genetic factors, , it can also be linked back to environmental factors and influences. A study by Van, Park and Jones (2001) aimed to see how the environment influences neurotic tendencies. Previous research had indicated that early stressful life events could influence neurotic tendencies. Results found that higher occurrence of traumatic early life events - defined as events before age 16 - including deaths, accidents, injuries, divorce and other crises, resulted in higher neurotic tendencies at adult ages. In participants in this study, the highest levels of neuroticism resulting from these environmental factors was observed in adults between the ages of 36 and 43. Van et al. thus concluded that early stressful life events could largely impact the prevalence of neurotic tendencies later in adulthood. Researchers also noted some genetic factors, stating that individuals with certain genetic patterns were more susceptible to being  effected by stressful events early in life (Van et al., 2001). These results indicate that neurotic individuals are influenced by more than just genetics and are largely influenced by environmental conditions as well. This emphasizes the point of nature and nurture working together to build personality and characteristics. The question is now, how neuroticism presents itself neurologically in more neurotic individuals.

Changes in Amygdala Activation Amongst Neurotic Individuals

The amygdala is known to be the emotional center of the brain, modulating mood disorders, emotions and instincts. It is part of the limbic system, a system in the brain known for the complex behaviors stated previously. In addition, the nucleus accumbens, which is adjacent to the amygdala, is also known to be part of the limbic system and responsible for emotional regulation and behavior. In the amygdala, the release of dopamine is commonly linked with building fear memories and responses. Higher amygdala activation is largely due to strong emotional drive or emotional experiences. The nucleus accumbens - an important player in the limbic system - works directly with the amygdala and other structures to regulate emotions. In particular, the nucleus accumbens is generally related to the release of dopamine and the feeling of pleasure that comes with dopamine release (Bienvenu, 2003). This paper will focus on these two areas in the brain and the roles they play in neurotic tendencies.

Neuroticism is not only a factor of personality; it is also commonly linked with different levels of amygdala activation in the brain. Bienvenu et al. notes that amygdala and cingulate cortex activation are associated with anxiety and mood disorders; those with higher levels of neuroticism typically are found to have higher amygdala activation. For example, there is increased amygdala activation in those with anxiety or depression, or other disorders that are commonly linked with neurotic personalities. This suggests that those that are highly neurotic may be more emotionally conflicted and have more arousal in comparison to those who display less neuroticism. The other proposal is that highly neurotic individuals are proposed to be more vigilant when processing conflict, especially in cases of emotion conflict and disagreement. This would suggest that amygdala activation in neurotics could largely be due to internal conflicts, which result in abnormal amygdala activation. By spending more time on the processing of emotions, neurotics have greater amygdala activation and conflict within the brain, potentially leading to higher amygdala activation (Haas, 2007).

Other studies have indicated that high levels of neuroticism are linked with relatively less inhibitory control over negative facial expression analysis and control. A study completed by Cremers et al. (2010) found that individuals who scored higher on the neurotic personality exam displayed enhanced connectivity between the right amygdala and right dorsomedial prefrontal cortex (dmPFC) during the processing of angry and sad faces. This allowed researchers to conclude that those with higher levels of neuroticism have less inhibitory control over negative facial expressions. This means that individuals that are highly neurotic tend to get more hung up over negative facial emotions and expressions, facilitating greater linkage between these two areas of the brain (Cremers, 2010).

Neurotic individuals are known to focus on internal states, and previous research has only found a link between increased focus and negative internal states. However, some recent studies have found that neurotic individuals tend to have higher activation in the amygdala in response to not only negative experiences, but to positive stimuli and events as well. Britton et al. (2007) note that individuals with higher neuroticism scores were directly associated with higher levels of activation in the dmPFC, an area known for experiencing positive emotions. In this case, neurotic individuals also tend to focus and ruminate on positive emotional states as well. This is an interesting study as it also highlights the overall self-rumination that neurotic individuals tend to experience, pulling from a more positive emotional perspective. This perspective is extremely important in removing the negative stigma behind neurotic individuals, and it can help us to highlight the positive sides of neurotic individuals (Britton et al., 2007). Overall, it can be concluded that neurotic individuals have a larger response regarding all emotions, due to the tendency to focus on internal emotional states, both good and bad.

A study by Aghanji (2014) also notes similar characteristics amongst neurotic individuals. The results of this study did not suggest any association between neurotic individuals and amygdala activation in the hypothesized regions of the ventral affective system—the subgenual anterior cingulate cortical, dorsomedial prefrontal cortex, dorsolateral prefrontal cortex and the orbitofrontal cortex- a stark contrast to other studies. However, it did find that there were significant differences amongst amygdala activation in neurotic individuals in different regions of the amygdala, including left amygdala resting state functional connectivity (RSFC) with the precuneus. This area of the brain plays a role in self-referential informational processing, such as perception and the processing of individual personality traits and self-descriptions. These results therefore note increased amygdala activity in the part of the brain that is generally linked with feelings of self-consciousness, remorse, self-confidence and responsibility. In addition, areas of the brain related to social interaction and understanding of other’s feelings showed  decreased amygdala activation (Aghanji, 2014). This emphasizes that the areas of the brain associated with self-reflective tendencies saw greater activation in comparison to that of social areas of the brain. It can therefore be inferred that this is due to neurotic personality traits and characteristics, as more neurotic individuals are more likely to suffer from anxiety or depression or rumination in their own thoughts, and less likely to build relationships with others around them due to the anxiety and depression they feel as well as the fear of rejection from others.

Addictive Tendencies

The  link between high levels of neuroticism and social media addiction can be determined through studying addiction tendencies. . Addiction is commonly thought of   in relation to drugs. However, from a broader sense of the word, addiction is defined as a “treatable, chronic, medical disease involving complex interactions among brain circuits, genetics, the environment and an individual’s life experiences. People with addiction use substances or engage in behaviors that become compulsive and often continue despite harmful consequences,” (American Society of Addictive Medicine, 2019). By this definition, addiction can be classified as a compulsive engagement in different behaviors. Therefore, social media addiction would depend on compulsive and repeated use of social media.

A metanalysis completed by Aghaii et al. (2012) explored the factors that influence addictive tendencies. This study found that environmental factors were linked directly with addiction in 61% of studies and individual personalities/genetics contributed to addictive tendencies in approximately 45% of participants in 16 different studies. Thus, by this metanalysis, environmental factors effect addictive tendencies more prevalently than individual and genetic factors. However, this analysis does not discount the importance of behavioral and genetic conditions that could also influence addictive tendencies and patterns (Aghaii et al., 2012). Ultimately, addiction is dependent on a variety of cofactors; therefore, it is important to understand how different personalities have differing susceptibilities to addiction.

Franken (2006) implemented Gray’s model of personality and addiction to attempt to link factors of personality to addictive tendencies. Gray’s model narrows down to two basic brain systems that control behavior and emotions: the behavioral inhibition system (BIS) and the behavioral approach system (BAS). Gray’s study concluded that the BAS is activated by stimuli attached to a reward and the BIS is activated by stimuli attached to a punishment or the removal of a reward (Gray, 1993). This study linked the release of dopamine to addictive tendencies in an individual; thus, if a behavior released more dopamine, an individual was found to have more addictive tendencies towards that behavior.

Franken’s present study found that the BAS system is heightened in drug addicts but notes that this seems to be on an individualized basis based on the substance that one is addicted to. Franken found that the heightened BAS system was found mostly in those more apt to be thrill seeking and reckless (Franken, 2006). This is important in understanding the topic at hand as neurotic individuals are generally the opposite of this: they tend to show hesitation in their actions, resulting in behaviors and tendencies that are generally less risky.

But then, why is there a link between internet addiction and neuroticism? Understanding the prevalence of internet addiction amongst neurotics will hopefully help answer this question in order to link social media addiction, neuroticism and brain region activation.

Social Media Addiction and Neuroticism

What is typically referred to as social media addiction is a growing problem in society, influenced by recent technological advances, including the creation of the smart phone, several popular social media sites (i.e. Facebook, Twitter, Snapchat, Instagram, etc.), and greater accessibility to the internet. Statistics from 2019 found that on average, adults spend over three hours of time on their phone a day. In 2018, over two billion people were present on social media, with adults spending about 153 minutes per day on social media on average (Broadband, 2019). This relationship between social media and the individual is even stronger in those with more neurotic tendencies. One researcher’s 2017 study specifically looked at two of the personality traits, neuroticism and extraversion, as predictors for social media use in relationship to the fear of missing out (FOMO) with attachment style as a moderator. This paper will highlight what this study found in relation to neuroticism in particular. To start, the study defined social media addiction as “the inability to control one’s social media use,” (Blackwell, 2017). Then the study talked about different types of attachment styles and provided predictions as to why anxiously attached individuals in particular, who often display neurotic tendencies, might become addicted to social media. Anxiously attached individuals fear rejection; thus, it is predicted they may use social media to connect with those around them in a way that reduces possibilities for rejection. They also noted that anxiously attached individuals are more likely to suffer from FOMO, the fear that others around them are having fun without them. This was a correlation study using anonymous surveys to analyze student’s social media use, personality characteristics and attachment styles. The results found suggest that neuroticism is a predictor of social media use and internet addiction; the researchers concluded that more neurotic individuals tend to feel more anxious about relationships, and so they tend to rely more heavily on social media to maintain those relationships. In addition, FOMO was a moderator that predicted social media use more than personality style, an interesting fact that could potentially relate back to the key characteristics of addiction (Blackwell, 2017). 

Similar findings were found amongst other researchers exploring neuroticism and social media overuse. Seidman (2013) also used neurotic individuals as a prediction of social media overuse. The results of this study found that amongst the individuals studied, the ones who were found to be more neurotic used Facebook more on average. Seidman predicted that this could be due to two different possibilities: 1) neurotic individuals seek Facebook as a way for them to experience feelings of belonging they may not feel in person to person contact, or 2) neurotic individuals may use Facebook as a safe place for their self-perseveration and identity (Seidman, 2013). These findings are consistent with previous findings, finding that neurotic individuals could potentially rely heavily on social media to fill a void in their life of social interaction caused by their anxious or negative feelings about themselves.

However, it is important to note that, in stark contrast to other studies, a study conducted by Wilson et al. (2009) did not find any correlation between social media use and neurotic tendencies. They suggest that neurotic tendencies are likely a predictor, but not a significantly associated factor leading to internet and social media use. The researchers in this study concluded that the results they obtained can be explained by the fact that neurotic young adults are more anxious and insecure in nature, and so they tend to dislike the idea of posting photos or information about themselves online where they could be criticized. They predict that rather, the high internet time seen in neurotic individuals is not from social media use, but from other outlets online. In addition, they looked at another factor – self-esteem – and its relation to social media addiction, and concluded that self-esteem could either increase or decrease social networking use, depending on the tone of feedback between both people on either side of the online conversation. With more positively received interaction, lower self-esteem could be linked to increased social media use, but with poorly received interaction, lower self-esteem would likely be linked to decreased social media use (Wilson et al., 2009). Overall, the findings of this study are an interesting paradox to previous studies that could largely be due to differences in culture. The individuals in this study were all Australian, whereas the previous studies pulled participants from American institutions and universities. Perhaps different cultural perspectives contribute to different personality traits.

Tying it all Together

Finally, research into how an individual’s sex affects their tendency to become addicted to social media was also explored. Different sexes tend to have different personality characteristics, with women being generally regarded as more “sensitive”, and men seen stereotypically to try to “shield their emotions.” Therefore, it would be interesting to see if the self-conscious characteristics associated with neuroticism are more present in one sex in comparison to the other.

A study completed in 2018 specifically aimed to look at social-media addiction and neuroticism between sexes. This study recruited Israeli College students and asked them to fill out self-reporting data. Researchers predicted that sex, neuroticism and well-being would moderate Facebook usage. The results found suggest that between men and women, more neurotic personality traits presented with lower well-being scores, once again emphasizing the negative effects of neurotic tendencies in individuals. In addition, researchers found differences in how neuroticism affects social media use between men and women. In this study, women high in neuroticism were more likely to have negative social networking site consequences in comparison to men (Turel et al., 2018). This is interesting as it indicates further that perhaps these social media struggles are moderated by a variety of characteristics: amygdala activation, sex differences, age or personality traits. This study is important in understanding how many cofactors can contribute to overall differences in social media addiction.

Although important, the results presented so far do not yet answer the question of why neurotic individuals show a trend to social media addiction, but don’t have the characteristics typical with drug addiction. Those who are more susceptible to addictive tendencies, in this case substance abuse, are generally more reckless and known to take more risks with their activities they are involved in. Meanwhile, neurotic individuals are typically described as reserved, more self-conscious and anxious - characteristics that directly confound with the typical drug or substance abuse. One inference that can be made to explain this disparity could be made in relation to the riskiness of behaviors associated with drug abuse and social media addiction. Addiction largely plays upon the reward system of the brain, commonly known to release the neurotransmitter dopamine for a feeling of pleasure right after the addictive behavior is completed. After drug use or alcohol use, a surge of dopamine is released in the nucleus accumbens. For example, cocaine, a commonly abused substance, leads to more dopamine in the synaptic cleft by block dopamine reuptake transporters; thus, allowing for a surge of dopamine to be present in the synaptic cleft (Harvard Health Publishing, 2011). This release of dopamine then causes a pleasurable feeling, creating a craving and drive to experience the behavior again for the rewarding feelings. 

Similarly, social media use is also believed to result in a release of neurotransmitters. Habitual social media use can lead to addiction because it has an unpredictable reward schedule. Using social media does not guarantee a good feeling or a bad feeling, but leaves users wondering what could happen next. This causes a variable reinforcement schedule, resulting in users becoming addicted to wondering when their next “good” or “pleasurable” feeling could come (Griffiths, 2018). It is debated whether dopamine is released in this variable reward schedule; however, Griffith notes that “the use of ‘like’ buttons [has] hijack[ed] the social reward systems of a user’s brain,” (Griffiths, 2018). In addition, Griffiths notes that Sean Parker, the founding president of Facebook, even acknowledges that the company aims for a like or comment to give “you a little dopamine hit,” (Parkin, 2018). This suggests reason to believe that receiving ‘likes’ could lead to a release of dopamine and cause a pleasurable feeling in a social media user’s mind, which could cause addiction in a similar way that drugs cause addiction. This is a hypothesis that has not been adequately confirmed or denied and which is still a research work in progress but completing further research into this topic seems promising. Overall, despite the fact that it has not been studied fully, for now it seems evident that dopamine could be a factor at play in addiction to social media and overuse of social media; further research will help to clarify whether or not it is a factor.

Exploring whether social media use causes dopamine to be released is also important as it has been assumed that architects of social media sites exploit a “vulnerability in human psychology,” (Parkin, 2018). In other words, social media creators play up on human psychology to ultimately try and build that addiction-like dopamine release. They also play up on the variable reward schedule to keep users on their toes and wanting more, building anticipation and a desire for the next great thing on social media. Thus, it has recently been coined that social media is a “persuasive technology,” meant to play off behavior and reward systems like the dopamine reward system (Parkin, 2018). Therefore, although the mechanism of social media addiction has not been fully pinned down, it could be largely due to several different emotional regulation areas in the brain that should be further researched.

Conclusion

To conclude, it can be inferred that the social media addiction epidemic linked to neurotic individuals versus other addictive tendencies could be largely due to the riskiness of the behavior. Those who are prone to drug abuse or substance abuse, generally are risk-takers, searching for pleasure. However, neurotic individuals could be using social media as a tool to facilitate the same feelings in a less risky way. Neurotic individuals might be hung up on the unknown factor of social media, causing anxiety and excitement, directly playing into their stereotypical characteristics.

Moreover, amygdala activation between drug addiction, neurotics and social media abusers could vary slightly as the same pleasurable feeling of dopamine release could be modulated in different brain regions, particularly the nucleus accumbens or amygdala. In this case, social media addiction may be modulated by the amygdala, like neuroticism, whereas, drug addiction and dependency could be modulated by the nucleus accumbens, perhaps similar to other personalities of the Big Five.

Overall, this is a new topic as social media presence has heightened in the past 10-15 years with the introduction of Myspace, Facebook, the smart phone, etc. This limits the analysis at hand because there is simply not enough deep diving information on social media addiction yet. A lot is unknown and future studies offer much, such as whether dopamine presence is linked to social media use. This is an expanding topic and has much to come in the research world.

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