There is no doubt that, for many psychological and sociological experiments, the less that the subject knows, the better.
Unfortunately, this intent can stray into harming people, intentionally or otherwise, and psychology associations across the world have to constantly update their ethical codes to incorporate new discoveries about the human mind.
Examples of Deception and Research
To show how ethical concerns have changed during the 20th century, it is useful to look at some examples.
The Stanford Prison Experiment and the BBC Follow Up.
Zimbardo was a professor at Stanford and did not fully understand the implications at the time. Looking back, with hindsight, there was not enough information given to prisoners and guards beforehand, and reasonable consent was not possible.
Possibly the gravest mistake he made was not pre-testing the participants, and the way that the advert was worded may have garnered responses from people more inclined towards masochistic and controlling behavior. Zimbardo was not a bad person, quite the opposite, but this infamous experiment highlighted the danger of mixing deception and research.
The BBC experiment, in 2002, tried to replicate the Stanford Prison Experiment, but used different techniques and ethical codes.
The experimenters ensured that the applicants were informed about the fact that they may be subject to emotional distress. The applicants were selected after careful psychological evaluation. A paramedic and psychology team watched 24/7, and any one of these had the right to halt the experiment immediately and intervene.
An ethical committee chaired by a member of parliament vetted the procedures first and gave the go-ahead for the experiment. Again, they could bring a complete halt to the proceedings. Unlike in Zimbardo's research, the Guards underwent some training and were told exactly what was, and what was not acceptable.
This experiment, whilst it would attract rigorous scrutiny, addressed the concerns about deception in research in the best way, and it has received less criticism than Zimbardo.
The addition of a consent form at the end allowing a subject to ask for their input to be removed would probably bring it into line with modern day values, so any deception within the experiment was minimized.
The Piliavin and Piliavin Experiment - Public Deception and Research
After the rape and murder of Kitty Genovese, where the victim allegedly screamed for 30 minutes whilst she was brutally killed and raped, raised questions about why no bystanders or neighbors intervened, or even phoned the police.
In response, Piliavin and Piliavin, realizing that a laboratory experiment with informed consent would not produce accurate enough results, designed an experiment where they would measure 'Good Samaritan' behavior upon unsuspecting members of the public traveling in a New York subway train.
A model, either apparently drunk or carrying a cane would collapse, and the amount of helpful interventions by members of the public would be determined.
The results of the experiment determined that people were generally very helpful, although a little more reluctant to help a drunk.
In terms of the ethical code governing deception and research, it could be argued that the experiment could be performed in no other way, as previous attempts showed.
If the participants possessed pre-information, and knew that they were being watched, the bystanders would be more likely to help. The usefulness of the results is also undoubted and unquestionable.
The murder caused a lot of publicity and it could be argued that such a study into behavior could lead to educational adjustments and cultural changes preventing a repeat.
For example, a publicity campaign asking people to intervene, or phone the emergency services if they felt too physically threatened, could justify the ethical risks.
The problem with the experiment is that there was no pre-experimental consent, and the experiment could have emotionally distressed people, either because they thought that somebody was hurt or due to guilt from their failure to help.
The fact that there was no psychological evaluation after the experiment, because the participants were unknown, means that this would not be allowed today.
There are some TV shows trying to perform similar experiments, with similar issues of consent, but they are always at least careful to explain to unwitting participants after the event. Many psychologists consider that these 'reality' shows stray across the line governing deception and research.
The Difficulty of Balancing Deception and Research
These two research studies are examples of how science has to constantly refine and update ethical codes.
The Tuskegee Syphilis Study is one evil extreme, but experiments like the above and the Milgram experiment show that even the best-intentioned research can end up straying onto the wrong side of the divide.
Deception in research is one area where balancing the needs for statistical accuracy and validity against ethics is always a very difficult process.
For most studies, the informed consent policy is used - when not used, an ethical committee must approve that the deception does not cause harm or distrust of research.