Indigenous communities in North America have distinct colonial histories with their own story of how their ancestors were able to survive the mass effort to take their land, resources, language, culture, and sometimes even their lives. These stories have been passed down orally and through the DNA of the descendants of survivors via epigenetics. The Historical Loss Scale (HLS) and Historical Loss Associated Symptoms Scale (HLASS) are two validated scales that measure historical trauma among Native Americans. However, as different Indigenous communities have different colonial histories, it is critical to ensure that tools used to measure historical trauma are valid for that specific community. When these scales are applied to Native Hawaiians, these measures may not provide an accurate picture of the historical trauma experienced by Native Hawaiians.

Exposure to war and violence has detrimental impacts on people’s lives, including economic, geographic, and social effects. In many cases, these impacts extend beyond the individual that directly experienced these mass trauma events and are transmitted to their offspring ^[1][2][3][1,2,3]. Indigenous historical trauma research developed out of research exploring the impact of the holocaust on the offspring of survivors. In addition to additional stress and traumatic life events, offspring of survivors perceived their parents as unable to satisfy their needs and lacking emotional resources ^[4][5][6][4,5,6].

Historical trauma, as defined by Brave Heart, is the “cumulative and collective emotional and psychological injury both over the life span and across generations [7]”, which emanates from massive group trauma [8]. She goes on to note that this trauma is derived from “cataclysmic, massive collective traumatic events, and the unresolved grief”, impacting personally as well as intergenerationally ^[9][10][11][9,10,11]. Unlike intergenerational trauma, historical trauma operates on three levels: (1) Individual, which includes both mental and physical health; (2) Familial, which covers parental bonding and transferred trauma; and (3) Communal, which incorporates the breakdown of culture, high rates of mental ailments, and health disparities [12]. Individual responses include anxiety, post-traumatic stress, and depression, while familial responses can be seen in the increased interest of later generations in ancestral trauma, such that it becomes an organizing concept for family systems ^[13][14][15][13,14,15]. Brave Heart calls these responses “unresolved grief” that is exhibited across generations that can be seen in American Indian (AI) communities.

American Indian tribal nations pre-exist the formation of the US. Prior to Western contact, tribal communities had strong social, political, and governing systems in place [16]. Although Indigenous communities did have some disease, the general level of health was quite high due to the nutrient-rich diet and active lifestyles of these societies ^[17][18][17,18]. As European settler–colonists began to entrench themselves into the “New World”, they brought with them foreign diseases that disrupted Indigenous social fabric ^[19][20][21][19,20,21]. Epidemics swept through communities leaving no one to gather or hunt, resulting in diminished food supplies and a reduction in physical resilience of individuals, which, in many cases, lead to death ^[22][23][22,23].

As the Indigenous population declined, as did their relative power vis-a-vis European settlers [24]. Additional mass trauma events were perpetrated on Indigenous communities, including war, physical violence, and rape. Treaties were re-negotiated, as the power dynamic changed to favor the European settlers-colonists, requiring tribes to cede portions of their territory or agree to reside on reservations. As tribal nations continued to struggle for survival, the colonies, and, later, the US, began to unilaterally abrogate treaties, further casting aside what was once a diplomatic relationship [25].

The Reservation era (1850–1887), a period of US–tribal policy focused on assimilating Indigenous people, brought with it many programs, schools, and training programs that mandated farming arid reservation lands and homesteading skills ^[26][27][26,27]. Indians were deemed legally incompetent, requiring a white man to oversee their finances, which led to significant theft and corruption [28]. Throughout this era, tribal languages and cultures were minimized through indirect and direct means, including children being taken from their families and placed in boarding schools ^[29][30][29,30]. Despite the current US–tribal framework supporting self-determination, Indigenous people continued to distrust the US government, likely a result of the ethnocide committed by the ancestors of the modern-day settlers ^[31][32][31,32].

In addition to the pioneering work of Brave Heart, other scholars have furthered the research platform related to historical trauma, understanding the impact of mass traumatic events along with the degradation of resilience producing activities. Sotero articulated how secondary generations experience historical trauma, even though they did not experience the actual trauma event [33]. A significant number of studies have found associations between a higher presence of historical trauma elements and negative health outcomes [34], such as increased substance use among Native youth [35]. However, these studies have yet to develop into generalizable practice and policy standards.

Although historical trauma has received increasing attention in Indigenous communities, only two validated measures exist that purport to measure historical trauma [36]. The complex nature of historical trauma means that it encompasses historic, intergenerational, and present-day trauma. As the standard diagnostic categories, such as posttraumatic stress disorder (PTSD), used by psychologists and counselors, only capture some of the symptoms of historical trauma [12], scholars, such as Brave Heart, advanced a significant research agenda around historical trauma. Sotero’s conceptual model of historical trauma described the mass trauma actions perpetrated by the settler population on Indigenous people that resulted in intergenerational historical trauma, especially as the collective historical trauma was passed from one generation to the next [33].

Under the weight of the colonization and assimilation of each generation of the Indigenous communities, they began to lose some of their traditional coping mechanisms that mediated the impact of the trauma [37]. Ultimately, the present generation carries not only current day racism and microaggressions but also the past lived experiences of their ancestors, resulting in intergenerational accumulation of trauma [38]. The increased health disparities that people see today among Indigenous people are, at least in part, the result of these traumas ^{[39][40][41][42]}[39,40,41,42].

Similar to American Indians, NHs had a strong governing system that centered around resource management. For hundreds of years prior to sustained Western contact, NHs were governed under a land management system, which divided land in ahupua’a or areas of land starting from the top of a mountain and tracing down to the ridgeline to the ocean ^[43][44][43,44]. Konohiki (resource managers) would build expertise over their lifetime and often across generations to understand how to effectively manage resources to ensure that the community had sufficient amounts of food, clean water, proper housing, and safety [45]. This system of governance resulted in systems of abundance that Hawaiians lived under for centuries.

The arrival of Captain Cook marked the beginning of many changes for NHs. One of the most impactful changes was the mass adoption of Christianity, which was brought to Hawai’i by missionaries soon after contact [46]. Early missionaries embraced Hawaiian language and used it to convert Hawaiians [47]. However, later missionaries began to push for social changes such as a change in attire to support increased modesty, use of the English language, and other policies that supported the assimilation into Western culture ^[48][49][48,49].

Sustained Western contact ushered in a number of threats to the perpetuation of Hawaiian culture, ancestral knowledge, and customary practices. Taking place from the Kingdom era through to the aftermath of the illegal overthrow of the Hawaiian Kingdom by the US, these threats included the condemnation of hula as lewd and an abomination, prohibition of speaking Hawaiian in the school system, and the promotion of Christian names over Hawaiian naming practices ^{[50][51][52][53][54]}[50,51,52,53,54]. Even schools that were meant to support Hawaiians operated using a deficit-based model, reinforcing the lower socio-economic status of Hawaiians and traumatizing Hawaiians ^[29][55][29,55]. In a matter of generations, Hawaiians went from the most literate nation in the world to having their government forcibly taken over by a group of non-Hawaiian businessmen with ties to the United States [56]. Hawaiians and scholars continue to debate the legality of Hawai’i’s position as the 50th state in America. Unlike federally recognized Native American tribes, NHs lack official legal recognition and self-determination, which reinforces the continued colonial legacy.

Hawaiian scholar and psychologist Rezentes coined the term kaumaha to describe the deeply seated, heavy sadness that resulted from colonization [57]. Kaumaha, or historical trauma, thus has been identified in NHs and operates similarly ^[58][59][60][58,59,60]. In fact, the concept of historical trauma also resonates with Hawaiian cultural values placed on mo’okuauhau or genealogy, which encourages Hawaiians to know not only their genealogy, but the storied histories of their ancestors. When these stories hold negative power, it adds to the emotional trauma experienced by later generations. The intergenerational nature of the effects of colonization can be seen through the disproportionate physical and mental health, education, and socio-economic outcomes experienced by NHs [57].

Currently, no measure specific to NHs exists to measure historical trauma. However, two studies did apply the HLS to NH. Pohkrel et al. applied the HLS to NH college students in a study focused on substance use among college students [61]. The research found an inverse association between historical trauma and substance use. The authors suggested that perceived discrimination mediated the effects of historical trauma and substance use. Five items were removed or modified in the Historical Loss Scale to better align with NH colonial experiences. Notable differences occurred when the adapted scale was applied to NH, including that NHs were more likely to report thinking about historical trauma on a yearly basis, but less likely to report thinking about historical trauma daily than AIs in Whitbeck’s study [36].

Alvarez et al.’s findings were similar. However, this research focused on māhū, or the lesbian, gay, bisexual, transgender, or queer population [62]. Alvarez conducted a crossover implementation of the HLS by, first, reinterpreting each item of the HLS and then conducting both interviews and focus groups with 22 NH. After applying the reinterpreted items of the HLS to māhū NH, they found that certain items such as loss of land, language, culture, and early death were endorsed by all participants. However, other items related to boarding schools, government officials, respect of children, and trust in colonizers were less endorsed. Finally, certain scale items were removed completely, as they were deemed to be irrelevant [62].