Psychologists play multiple roles in informing the law as advisers, evaluators, and reformers. As advisers,
a psychologist can provide expert testimony in a legal proceeding, file amicus curiae briefs to educate
judges on relevant psychological research or be a trial consultant. A psychologist may evaluate the
effectiveness of a program or public policy as an evaluator. There are times when programs may be put
into place so that psychologists can collect and analyze the data on these programs and policies in order
to assist in determining the effectiveness and if they meet the stated goals (Costanzo & Krauss, 2021).
As reformers, psychologists will ask whether they have adequate evidence to suggest changes in a
system based on history and tradition to improve them. Many psychologists are uncomfortable when it
comes to the role of the reformer. Promoting change means that the psychologist must step away from
the role of being an objective scientist (Costanzo & Krauss, 2021). When considering the role of a
reformer the individual would serve more as an activist who uses litigation to try and advance social
change in the law. This usually would be aided by finding or using a psychologist whose research
supports their case.
Other areas of psychology that are relevant to some aspects of law and the legal system include
developmental, social, clinical, and cognitive psychology. Psychologists in a court of law may be asked to
speak on topics within their expertise. Following a divorce, a developmental psychologist may be called
to lecture on custody arrangements that will promote the child's healthy development. Social
psychologists can analyze if the group dynamic of a jury influences their verdicts. Clinical psychologists
may address whether a defendant is competent to stand trial and finally, a cognitive psychologist could
be requested to assess the accuracy of expert testimony (Costanzo & Krauss, 2021).
Psychologists play diverse roles in informing the legal field, serving as advisors, evaluators, and
reformers. As advisors, psychologists can offer expert testimony during legal proceedings, submit amicus
curiae briefs to educate judges about pertinent psychological research or provide their expertise as trial
consultants. As evaluators, psychologists may assess the effectiveness of programs or public policies,
collecting and analyzing data to determine if they align with their stated objectives (Costanzo & Krauss,
2021). When psychologists take on the role of reformers, they question whether there is sufficient
evidence to advocate for changes in established legal systems, often challenging tradition and historical
norms. This role requires psychologists to step out of their traditional objective scientist role and
become more akin to activists who utilize litigation to drive social change within the legal framework,
often enlisting the support of psychologists whose research aligns with their cause.
Beyond these roles, various subfields of psychology, such as developmental, social, clinical, and cognitive
psychology, have relevance within the legal domain. Psychologists in legal settings may be called upon to
share their expertise on specific topics. For instance, in divorce cases, a developmental psychologist
might be summoned to provide insights on custody arrangements that support a child's healthy
development. Social psychologists can examine how group dynamics within a jury might influence their
verdicts. Clinical psychologists might evaluate a defendant's competency to stand trial, while cognitive
psychologists may be tasked with assessing the accuracy of expert testimony (Costanzo & Krauss, 2021).
These diverse roles and specialties within psychology collectively contribute to the multifaceted
intersection between psychology and the legal system.
There are three core differences when examining the cultures of psychology and law. Most of these
conflicting ideas stem from contrasting each culture’s goals, methods, and styles. One of the first and
basic concepts often addressed is that psychology attempts to describe how people behave, whereas
law attempts to dictate how people should behave (Costanzo & Krauss, 2021). The primary goal of
psychology is to regulate human behavior. Psychological science focuses on finding the truth, while the
legal system focuses on obtaining justice. Additionally, psychology emphasizes group characteristics,
while law emphasizes the individual.
Regarding methods, the law is based on authority, while psychology is based on empiricism. Psychology
advances through scientific research, while law advances through court rulings and relies heavily on
citing precedence; the law is also fluid and continually advancing. The judge's goal is not to stray too far
from an established precedent. In psychology, the future-oriented culture depends on conducting
ongoing research to obtain new data.
According to the Code of Professional Ethics, lawyers must be advocates for their clients. In law, the
attorney has to take their client's side. On the other hand, psychologists are more objective in their
interpretation of data. It is typical for researching psychologists to disagree about the interpretation of
data or defend a theory. Often, psychologists assume objective interpretations of their data even though
they may subscribe to specific theories. (Costanzo & Krauss, 2021).
When comparing the cultures of psychology and law, three fundamental distinctions arise, rooted in
differences in their objectives, methodologies, and approaches. One primary distinction lies in their
overarching goals: Psychology aims to describe human behavior, while law seeks to prescribe how
people ought to behave (Costanzo & Krauss, 2021). Psychology's chief mission is to understand and
regulate human conduct, emphasizing the pursuit of truth, while the legal system is primarily concerned
with achieving justice, focusing on individual cases.
The divergence between these fields extends to their methods as well. Law relies on established
authority and precedent, while psychology is grounded in empirical research. Psychology advances
through systematic scientific investigation, continuously seeking new data and insights. In contrast, the
legal system evolves through court rulings and the reference to precedent, with judges striving to stay
within established boundaries.
Another critical contrast is the role of professionals in these domains. Attorneys, as per the Code of
Professional Ethics, are mandated to be advocates for their clients, firmly taking their side in legal
matters. Conversely, psychologists adopt a more objective stance when interpreting data, allowing room
for differing perspectives and theories among research psychologists. Despite these variations,
psychologists maintain objectivity in data interpretation, even if they hold specific theoretical positions
(Costanzo & Krauss, 2021). These distinctions in goals, methodologies, and roles underscore the unique
cultures of psychology and law.
At the most basic level, the primary difference between psychology and law is that "psychology tells us
how people actually behave, and the law tells us how people ought to behave" (Costanzo & Krauss,
2021). The law seeks to regulate human behavior and administer punishment to those who behave in a
way in which the law bids to render an approximation of justice. It is an approximation because the law
aims to resolve disputes by assimilating the haziness of a case and rendering a final, equivocal decision
in a clear ruling. The law emphasizes individual cases that can be precedents for future cases and
lawyers who advocate for a particular version of events or interpretation of evidence (Costanzo &
Krauss, 2021).
In contrast, psychology has a primary goal of providing complete and accurate explanations of human
behavior while striving for an approximation of truth. Psychology emphasizes the characteristics of
groups and is based on empiricism. Psychological scientists live in a future-oriented culture where they
believe our current understanding of human behavior should be continually revised as there is new and
extensive data forthcoming all of the time. Psychology's ideal is objectivity despite the humanness of
researchers who may have their personal values influence their research topics; in other words, some
researchers might be biased regarding specific topics. The scientific community helps to keep objectivity
in research findings through published research findings that are then scrutinized by other members of
the scientific community (Costanzo & Krauss, 2021).
Overall, the law utilizes case-methods techniques, whereas psychology employs scientific methods.
Psychology emphasizes the possibility of a cause or effect, while the law demands a clear-cut solution.
Laws must determine the matter in a fair, impartial, and just manner, while psychology focuses on
gathering evidence and data to support the truth. Based on this information, the system that is more
open to change is psychology. Even if psychology research can only offer partial solutions, it can provide
insight and the ability to reform the justice system in some issues.
At its core, the critical distinction between psychology and law lies in their fundamental objectives, as
succinctly stated by Costanzo and Krauss (2021): "Psychology tells us how people actually behave, and
the law tells us how people ought to behave." The law's primary function is to govern human behavior,
administering consequences to those who act contrary to its prescribed standards in pursuit of an
approximation of justice. This approximation stems from the law's role in resolving disputes by clarifying
the complexities of a case and delivering a definitive, albeit sometimes ambiguous, judgment. It
emphasizes individual cases that can serve as precedents for future legal matters, with lawyers
advocating specific interpretations of events and evidence.
In contrast, psychology's central mission is to provide comprehensive and accurate explanations for
human behavior, with a commitment to approximating the truth. Psychology focuses on the attributes
of groups and operates within an empirical framework. Psychological scientists operate within a
forward-looking culture, continuously revising our understanding of human behavior as new and
extensive data becomes available. Objectivity is the ideal in psychology, even though researchers,
influenced by personal values, may introduce biases in their research topics. The scientific community
plays a role in maintaining objectivity by subjecting published research findings to scrutiny by peers
(Costanzo & Krauss, 2021).
In essence, the law employs case-method techniques, while psychology relies on scientific methods.
Psychology delves into the potential cause-and-effect relationships, while the law demands clear-cut
solutions. Legal processes must address matters in a fair, impartial, and just manner, whereas
psychology concentrates on collecting evidence and data to uncover the truth. In light of this,
psychology emerges as a field more amenable to change. Although psychology's research may only offer
partial solutions, it provides valuable insights and the potential for reform within the justice system,
particularly in addressing specific issues.
It can be possibly tricky for a psychologist to maintain their impartiality as a scientist in fulfilling their
role as an expert in court for several reasons. The first reason is that the U.S. legal system is adversarial
in nature; it pits one side against another, whereas traditionally, science does not have a specific side.
Science is objective in seeking to explain rather than conduct a biased search for facts and then
administer punishment. Another reason is that when expert witnesses are hired by either the
government or a defense team, there are expectations that the expert will craft the research findings in
a way that is favorable to the side that has hired them. Such methods then present an ethical dilemma.
Because of the expectation of experts to support the side who hired them, lawyers will ‘shop around’ to
find the expert that will support their case the most and their version of events in the case. An expert
may have personal ideals or convictions that they may want to advocate for by using their own research
to support the legal team that aligns with their ideals or convictions. The fourth reason is that some
experts assume the role of ‘hired gun’ when they testify in court, making unequivocal statements
without the research to support those (Costanzo & Krauss, 2021).
A final reason might be that being an influential expert in court requires presenting a clear-cut and easy-
to-understand picture for the jury’s comprehension of an argument. Science is rarely presented in clear-
cut or straightforward language. An expert may seek to promote particular beliefs or values that they
hold, and psychologists must behave ethically. Psychological experts must weigh all data, opinions, and
rival hypotheses impartially. Otherwise, they diminish their ability to practice competently (Costanzo &
Krauss, 2021).
Psychologists often encounter challenges in maintaining their objectivity as scientists while serving as
expert witnesses in court, primarily due to several reasons. First, the adversarial nature of the U.S. legal
system, where opposing sides compete, clashes with the traditional objectivity of science, which seeks
to explain without bias and administer justice impartially. Second, when either the prosecution or the
defense hires an expert witness, there is an expectation that these experts will present their research
findings favorably to the hiring party, creating ethical dilemmas.
Furthermore, this expectation leads lawyers to shop for experts who align with their case, potentially
compromising the experts' objectivity. Some experts may have personal beliefs or convictions they wish
to advocate for, using their research to support a legal team that shares their values. Additionally, there
is a risk of experts assuming the role of "hired guns," making unequivocal statements in court without
substantial research backing (Costanzo & Krauss, 2021).
Another challenge arises from the need for expert witnesses to present information in a clear and easily
understandable manner for the jury. Science is often complex and nuanced, making it challenging to
simplify for the courtroom. While experts may have personal beliefs or values, they must adhere to
ethical standards and impartially consider all data, opinions, and alternative hypotheses to maintain
their competence (Costanzo & Krauss, 2021). These multifaceted challenges highlight the delicate
balance that psychologists must strike when serving as expert witnesses in the legal arena.
There most certainly can be issues when having trial judges act as the gatekeeper. The problem with
having trial judges as "gatekeepers" is that they cannot be expected to know everything, especially
about topics outside their specialized field of study. According to Costanzo and Krauss (2021), "If judges
are to serve as effective gatekeepers, they need to assume responsibility for learning about scientific
methods." A judge may poorly understand scientific methods as judges do not usually have previous
training in various scientific research or methods. Judges are human, and there can be instances where,
if they have a limited understanding of scientific methods, they also are at risk of unintentionally being
subject to human biases, which can affect their decisions on what scientific evidence to allow in court.
A proposed solution is cross-disciplinary education, which is a way to increase the use of social science
by the legal system. Exposure to psychological science by a graduate school program or through
integrating more psychological science into law schools will educate and likely open up students to
being more receptive to psychological sciences testimony in the courtroom (Costanzo & Krauss, 2021).
Using trial judges as gatekeepers in the legal system presents particular challenges. The primary issue
stems from the judges' limitations in knowledge, particularly regarding subjects outside their specialized
field. As Costanzo and Krauss (2021) suggest, for judges to effectively serve as gatekeepers, they must be
responsible for familiarizing themselves with scientific methods. However, judges typically lack training
in diverse scientific research and methodologies, potentially leading to a limited understanding of these
methods. Judges may inadvertently be influenced by personal biases when admitting scientific evidence
into court proceedings.
One potential solution to this problem is implementing cross-disciplinary education aimed at enhancing
the integration of social science into the legal system. This can be achieved through exposure to
psychological science within graduate school programs or by incorporating more psychological science
into law school curricula. Such educational initiatives can better equip students with an understanding of
psychological science, making them more receptive to psychological testimony in the courtroom
(Costanzo & Krauss, 2021). This approach addresses the knowledge gap and fosters a more informed
and impartial judicial system.
Powered by TCPDF (www.tcpdf.org)
