Affects are considered as the paramount motivational foundation of human behavior, contributing a significant proportion to the formation of the individuals’ temperament and personality (Kernberg, 2015). In recent decades, several attempts were made to differentiate and categorize basic affective systems (e.g., Izard, 1992; Panksepp, 1998; Ekman, 1999; Krause, 2012). In contrast to more cognitively oriented emotion/affect models, Panksepp (1998) emphasized the role of subcortical brain areas in the emergence of primary emotions [in Affective Neuroscience (AN) theory, affect is usually used synonymous with the term emotion]. Based on ethological research, he distinguished seven primary emotion networks, neuroanatomically located between the Periaqueductal Gray (PAG) and the limbic forebrain (Panksepp, 1998; Panksepp and Biven, 2012). These cross-species primary-process systems are assumed to act as prototype emotional states, which can be evoked via artificially induced stimulation (Panksepp and Watt, 2011). The Affective Neuroscience Personality Scales (ANPS; Davis et al., 2003) aim to measure six dimensions of these primary emotion systems including SEEKING, ANGER, FEAR, PLAY, SADNESS, CARE, and asses an additional spirituality scale.

While also conceptualized as a primary emotion, LUST was excluded from operationalization in the ANPS as the authors assumed that it “seems less relevant to current conceptualizations of human personality and we also suspected that it may potentially be an affective factor that people would not wish to be frank about, and thus may contaminate frankness on the other scales” (Davis and Panksepp, 2011, p. 1949). Nevertheless, LUST – defined as the “systems that contribute distinctly to female and male sexuality and associated erotic feelings” (Panksepp, 2004, p. 52) – remains a pivotal part of AN and related neuropsychoanalytic theory, involved in important aspects of etiological models concerning psychiatric disorders (Panksepp, 2004; Boeker et al., 2018). Accordingly, it appears sensible to construct a standardized measurement of this dimension in order to facilitate psychometrically oriented neuropsychoanalytic research. This demand is further highlighted by recent progress in this field achieved via the usage of the ANPS concerning investigations of primary emotions and its relationship to personality and phenomena of clinical psychology (Marengo et al., 2021; Montag et al., 2021).

Yet, to the best of our knowledge, no publicly available LUST scale exists until this day. One of the few trackable references to the LUST concept in relation to the ANPS can be found in a conference paper by Lotter and Dauphin (2014), which investigated the relationship between the ANPS and the Sexual Desire Inventory-2 (SDI-2; Spector et al., 1996), indicating a positive correlation between dyadic sexual desire and SEEK and PLAY as well as solitary and total sexual desire with SEEK and ANGER.

van der Westhuizen and Solms (2015) describe the development of a LUST measurement in context with the investigation of social dominance. According to the authors, the scale exhibited good internal consistency and was conceptualized via the assessment of “sexual desire, physiological arousal and sexual mentation.” However, this LUST scale was not made publicly available. Nevertheless, the authors reported moderate positive correlations between LUST and SEEKING and PLAY, small positive correlation with CARE and DOMINANCE as well as a small negative correlation with FEAR.

Another attempt to measure LUST was made by Dolce et al. (2020), who investigated a primary emotion driven personality concept by the means of neuronal networks training (Dolce et al., 2020). While the conceptual strategy of their newly developed self-rate measurement differs rather drastically from the original ANPS, the questionnaire primarily aims to achieve a high predictive validity with respect to psychiatric disorders. Therefore, in its current form, LUST is inversely assessed by three items which focus on inappetence, sadness and loneliness in social situations.

Based on its original definition, the LUST system is linked to feelings of pleasure, sexual urges and gratification, and is reciprocally connected to the SEEKING network (Panksepp, 1998; Solms and Turnbull, 2002; Panksepp and Biven, 2012). Its activation diminishes SEEKING driven appetence behavior and triggers feelings of satisfaction, serving as reward mediating substrate necessary for learning (Solms and Turnbull, 2002). This dichotomy between SEEKING and LUST largely corresponds to Robinson and Berridge’s (2000) differentiation between “wanting” and “liking.” In correspondence to this, the process of learning is understood as a coupling between psychomotor SEEKING impulses (“wanting”) and the experience of pleasure mediated by the LUST system (“liking”).

Inferred from animal model, the LUST network is assumed to consist of a complex group of structures, descending from the hypothalamus to the posterior parts of the midbrain (see Figure 1; Panksepp, 1998; Solms and Turnbull, 2002). Most authors agree that the LUST system is composed of the Bed nucleus of the stria terminalis, the central tegmental field, the preoptic area and the ventromedial hypothalamus, the Nucleus accumbens shell, septum area and the ventral Periaqueductal gray (Solms and Turnbull, 2002; Holstege and Huynh, 2011; Panksepp and Biven, 2012; Berridge and Kringelbach, 2015; Hashikawa et al., 2016). Neurochemically, the LUST system is largely controlled by endorphins acting on mu, delta- and kappa-opioid receptors in the Nucleus accumbens shell, and hormones like vasopressin, testosterone and oxytocin (Solms and Turnbull, 2011; Panksepp and Biven, 2012; Berridge and Kringelbach, 2015).

Moreover, recent studies in humans investigating the neural effects of orgasms with PET scans (Georgiadis et al., 2006; Holstege and Huynh, 2011) observed increased blood flow within the upper brainstem and cerebellum. Men showed increased activation in the insula, while women exhibited increased activation in the somatomotor and somatosensory cortex and a deactivation in the left temporal lobe and ventral prefrontal cortex.

Regarding the clinical significance of the LUST system, Panksepp (2004) exclusively proposed associations with disorders directly related to sexuality like sexual dysfunctions, sexual addictions, fetishes, and excessive jealousy. However, with regard to empirical research it seems plausible that dysfunctions of the LUST-system might be involved in a broad range of psychopathologies like affective disorders (Rokach, 2019), addictions (Kumsar et al., 2016), personality disorders (Collazzoni et al., 2017) and schizophrenia (Kelly and Conley, 2004). Yet, while there is growing evidence regarding associations between most primary emotions dispositions and psychopathology (Montag et al., 2021), due to the current lack of appropriate research instruments very little is known about the role of LUST.

As for associations with other personality traits, the current state of psychodynamic literature suggests associations between increased attachment security and personality functioning with a predominance of positive affective traits (Arbeitskreis OPD-2, 2008; Krause, 2012), an assumption supported by recent empirical evidence (Fuchshuber et al., 2019). Thus, it seems plausible to assume that a measure of LUST is positively correlated with increased personality functioning and attachment security. However, with research investigating the role of attachment security in connection to the related concept of erotophilia [defined as positive respond and attitude bias toward sexual cues (Fisher et al., 1988)], indicating no significant correlations, this relationship seems less clear (Bogaert and Sadava, 2002). Despite conceptual overlaps between both erotophilia and a disposition toward LUST, the transferability of this result remains uncertain, as erotophilia might be more oriented toward conscious attitudes regarding sexuality than the personality trait LUST, defined by the individual’s ability to attain sexual desire and pleasure.

This study aimed to be a building block toward the development of a self-rate measurement for the operationalization of LUST as proposed by Panksepp (1998). The psychometric properties presented in this paper suggest high reliabilities, normal distribution, good structural validity and a nomological network conforming to our hypotheses of both the long- and short-version of the proposed L-scales.

With respect to reliability, L-12 and L-5 exhibited excellent and good internal consistency, respectively, with comparable or even higher Cronbach’s α than the scales of the ANPS. For future studies further markers of reliability (e.g., split half or retest reliability) should be estimated. Additionally, inspection of skewness and kurtosis suggested a normal distribution of both scales with regard to a healthy population, again resonating with the characteristics of original ANPS (Davis et al., 2003; Davis and Panksepp, 2011).

Confirmatory factor analysis of L-12 revealed a bifactorial structure, with one general latent factor and two residual factors which seem to reflect specific variance regarding different answering styles with respect to items formulated positively vs. items which assessed LUST inversely. Alternatively, this result might be interpreted as residual variance caused by items concerning orgasms and items operationalizing disgust and shame, respectively. However, this effect vanished in the short version. L-5 exhibited excellent model fit in a single factor model, making it especially useful for studies applying structural equation modeling.

As the original version of the ANPS is often considered too long, currently two brief versions of the questionnaire have been developed, namely the ANPS short (ANPS-S, Pingault et al., 2012), and the brief ANPS (BANPS, Barrett et al., 2013). According to Pedersen et al. (2014) short versions generally improve the psychometric properties of the ANPS, however, the authors abstained from constructing a corresponding LUST scales. In this context, the L-5 scale might prove itself as a practical supplement for both ANPS short versions. In correspondence to this, the present form of the L-Scales was constructed in accordance with 5-point response format of the BANPS and consequently differs from 4-point format of the original ANPS.

The construction of the L-scales was aimed to be closely aligned to the original definition of LUST as introduced by Panksepp (1998, 2012), hence the investigated items consist of statements associated with eroticism, sexual enjoyment and pleasure. Of note, for the short version of the questionnaire, all statements which mentioned orgasms had to be deleted in order to establish a robust single-factor structure. Considering significant sex differences in the frequency of orgasms during intercourse (Frederick et al., 2018), the exclusion of statements focused on orgasms might explain the disappearance of sex differences in the short version. Nevertheless, both L-12 and L-5 exhibit a strong intercorrelation and a very similar correlation pattern with external criteria.

In correspondence to this, the L-scales exhibited moderate positive correlations with dispositions toward SEEKING and PLAY, while there were only small to non-significant correlations with CARE. Furthermore, both scales showed moderate negative correlations with SADNESS and FEAR, whereas both were independent of ANGER. Accordingly, the L-scales appear to be more inversely related to negative primary emotions than the scale developed by van der Westhuizen and Solms (2015). Hence, the results resonate with current neuropsychoanalytic literature, which assumes underlying drives (libidinal vs. destructive) acting as a latent grouping mechanism for affects (Krause, 2012; Kernberg, 2015; Boeker et al., 2018). However, further studies employing structural equation modeling which consider all seven primary emotions in a single model should be done to further investigate this hypothesis.

In accordance with the current psychodynamic understanding of the functional role of attachment and personality structure regarding affect regulation (Krause, 2012; Kernberg, 2015; Fonagy, 2018), the observed positive correlations between LUST and attachment security as well as more mature personality structure echo recent evidence indicating secure attachment and personality functioning to predict a pattern of increased positive and decreased negative primary emotions (Fuchshuber et al., 2019).

Along these lines, LUST appeared to be negatively related to increased psychiatric symptom burden. More detailed inspection suggests that this is predominantly driven by its negative association with depressive symptoms. Nevertheless, we also found significant (but small) negative correlations with symptoms of anxiety and somatization. These findings are in agreement with the current review of Rokach (2019), who detected that sexual dysfunctions are a wide spread concomitant of affective disorders. With regard to clinically relevant associations proposed by Panksepp (2004) future research should investigate the relationship between the L-scales and pathological jealousy and hypersexuality.

What is more, neither scale showed a significant correlation with spirituality as assessed with the ANPS. Relatively little is known about the relationship between LUST and spirituality, however, Brelsford et al. (2011) reported findings indicating a moderate negative correlation of sexuality and spirituality. Nevertheless, considering spiritual traditions which involve sexual practices (e.g., Tantra) further research may be needed to evaluate this relationship in more detail.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by the Medical University of Graz. The patients/participants provided their written informed consent to participate in this study.

JF conducted the all statistical analysis and wrote the first draft of the manuscript. EJ, MH-R, and HU read the manuscript and made some critical comments. JF, MH-R, EJ, and HU revised the whole manuscript. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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