INTRODUCTION There are many theories as to whether sunlight is beneficial to learning capabilities. Psychologists as well as energy experts have been discussing for some time now the different consequences of sunlight and artificial lighting. Natural light contains ultraviolet light humans need to synthesize vitamin D, which aids in the absorption of minerals, helps regulate heart problems and cholesterol, and is beneficial in treating breathing diseases and obesity. Light passing through the eyes, reaches the hypothalamus, which regulates emotional balance, activity/sleep patterns, as well as the autonomic nervous system. The autonomic nervous system then regulates the endocrine system. Part of the endocrine system known as the pineal gland reacts to natural light and thus influences a person’s daily biorhythms, motor activities, sleeping pattern, temperature, immune system, and growth. According to a previous study, ACTH and cortisone endocrine hormones are excessively produced in the absence of natural lighting. These findings suggest an increase in stress, ill-mood, negative behavior, as well as a decrease in learning capabilities in the absence of natural lighting (Bright Side Lighting). Some studies say sunlit rooms provide more efficient, productive, and cheerful people, or that students with higher test scores attend school in rooms with wide windows or skylights that allow sunlight in the learning environment. For example, over one-half of the 160,000 students observed in a recent study developed deficiencies related to the amount of sunlight available in their learning environments, by the time they graduated from elementary school. The environment was improved by adding better, brighter lighting, sunlight, more organized seating, and a cleaner learning area. After the lighting, seating, and decorations in the students’ environments were enhanced, the negative deficiencies were dramatically reduced when measured six months later. In fact, positive academic components, such as test-taking abilities, dramatically increased. The students exhibited healthier, happier personas as well as made better grades (Bright Side Lighting). In a study released by Heschong Mahone Group, an energy consulting firm for the California Board for Energy Efficiency and the Pacific Gas and Electric Company, 750 different classrooms were surveyed to determine testing differences regarding the lighting environment. The students were tested in the beginning of the school year, as well as at the end. The final comparison showed that students with the most sunlight in their learning environment, through wide windows and/or skylights, exhibited faster testing capabilities. Their scores were also 2 points higher on reading test questions, and 2.3 points higher on math questions (Heschong Mahone Group, 1999). Another interesting aspect to compare, however, involves morning-type people versus evening-type people. In a study conducted by Anderson, Petros, Beckwith, Mitchell, and Fristz (1991), college age participants were identified as either morning or evening type, and then their speed of remembering long-term memory information was examined. The participants were given sets of word pairs and asked to choose whether the words were identical, had the same name, or were of the same semantic category. Congruent to the morningness- eveningness-type, morning-type participants’ performance decreased as the day progressed, while the evening-type participants’ performance improved as the day progressed (Anderson et al. 1991). Another study, by Khaleque (1999), examined the quality of life for shift workers and their morningness- eveningness-types. Khaleque discovered that reducing the late shifts and adjusting the work schedule to support the morningness- eveningness-type of the worker improved their adaptability, tolerance, and overall quality of life. In Khaleque’s study, the quality of sleep for evening-type shift workers was discovered to be much better than the quality of sleep for the morning-type shift workers. This study, which analyzed the sleep, health, and well-being of male industrial shift workers, suggested that evening type people are better adapted for shift work and are less likely to suffer than morning type people. In a study by Kerkhof (1998), participants were asked to keep sleep-wake logbooks with their daily records of their moods and alertness. These subjective items were measured about every three hours. The morning-type individuals reported their best mood was in the early morning, with a peak of alertness around eleven in the morning. The evening-type individuals reported that their moods improved gradually throughout the day, and their alertness increased as the day progressed. This information could easily be utilized for determining class or work schedules for different types of people. Very little research, however, has been conducted to determine testing abilities of morning- and evening-types in regards to the lighting: sunlight versus florescent lighting. Thus, through this study, the effects of sunlight and florescent lighting were studied on morning and evening type participants in the morning and evening. It was predicted that if a morning-type person and an eveningness-type person were tested in the early morning with direct sunlight, then the morning-type person would score higher than the evening-type person, and thus the morning-type person tested in direct sunlight would also score higher than the morning-evening people tested in florescent lighting. Also, if an evening-type person and a morning-type person were tested in the evening with direct sunlight, then the evening-type person scored higher than the morning-type person, as well as scored higher than the evening-morning groups tested in florescent lighting. The variables pertinent to this study were time, morning- or evening-type, lighting, and the test. The independent variables included the use of sunlight or florescent lighting, which was manipulated by a large sliding curtain in the testing room. Another independent variable was the morning- evening-type of the participants. The third independent variable was the morning or evening testing time. Half of the morning-type participants were tested in the morning, and the other half were tested in the evening. Similarly, half of the evening-type participants were tested in the morning, and the other half were tested in the evening.
Eighty female students from Loyola University New Orleans ranging in age from 18 to 24 volunteered to participate in this study. The volunteers were offered food as an incentive, and some psychology professors gave extra credit to their students that participated in this study. Convenience sampling was used to obtain participants, although announced via email and through the school’s faculty. Quota sampling was also utilized. Then, participants were divided into characteristically morning- or evening-type groups, as determined by the Self-Assessment Questionnaire to Determine Morningness-Eveningness (Horne & Ostberg, 1970). The eighty female students were then divided into morning or afternoon testing time periods, as well as separate groups for sunlight or florescent lighting in the testing environment. Thus, there were eight separate groups containing 10 female psychology students studied, which are shown in Table 1.
The materials include a testing location in Market Hall at Loyola University New Orleans. There were window curtains that controlled for the lighting. They were either drawn shut with florescent lighting employed or left open with the sunlight utilized instead of artificial lighting. The participants sat in school seat/desk combinations. They used pens for the testing packets. The participants were given informed consent forms to read and sign. After they signed the consent forms, the participants were handed testing packets that contain demographic questions, the Self-Assessment Questionnaire to Determine Morningness-Eveningness (Horne & Ostberg, 1970), and SAT math questions (“4Tests.com”). The demographic questions concerned information such as race, math ability, major, and age. The Self-Assessment Questionnaire to Determine Morningness-Eveningness contained 5-point range questions that determine the participants’ degree of morning type or evening type personality (Horne & Ostberg, 1970). The SAT math questions were a compilation of 10 past SAT multiple-choice math questions (“4Tests.com”).
This study was a quasi-experimental 2x2x2 between-groups study. The independent variables included sunlight versus florescent light, morning-evening types, and morning or evening testing times. The curtain drawn or open manipulated the lighting. When the curtain was opened, the sunlight was the source of light for the participants, and when the curtain was closed, the florescent light was the only source of light. The morning or evening type was also tested in order to decide which group the participants were put into. A morning-type person was described as a person who displayed an earlier circadian peak time, higher daytime temperature, and better alertness from sunrise to around noon. The morning types also retired and arose earlier than evening types. An evening-type person was a person who displayed a later circadian peak time, higher nighttime temperature, and better alertness as the afternoon progresses into the evening (Anderson et al. 1991). Circadian rhythms, or biological clocks, were characterized by biological activities or functions that occurred in 24-hour cycles (Myers, 2001). In the Self-Assessment Questionnaire to Determine Morningness-Eveningness, the circadian rhythms referred to a person’s “feeling best” rhythms (Horne & Ostberg, 1970). For example, half of the morning-type participants were tested in the morning. The time was also manipulated. Half of the participants were tested at 8:30am, and the other half were tested at 5:30pm. Half of the morning-type people that were tested in the morning under florescent light and the evening half of the evening-type participants that were tested under florescent lighting made up the control groups because they were tested in their natural environment. The dependent variable was the participants’ testing ability measured through performance on the SAT math problems. The study took place in a Market Hall classroom at Loyola University that contained a spacious window and movable curtains. The participants met at either 8:30 a.m. or 5:30 p.m. Monday, Wednesday, or Friday. One morning-type group that met at 8:30 a.m., one morning-type group that met at 5:30 a.m., one evening-type group that met at 8:30 a.m., and one evening-type group that met at 5:30 p.m. were administered the SAT math test with florescent lighting and the window curtains drawn. The other morning-type group that met at 8:30 a.m., morning-type group that met at 5:30 a.m., evening-type group that met at 8:30 a.m., and evening-type group that met at 5:30 p.m. were given the test with the sunlight visible through the window and the artificial light turned off. Participants signed consent forms that outlined the details of this study before they participated in it in order to insure their understanding. They were asked to fill out demographic information, the Self-Assessment Questionnaire to Determine Morningness-Eveningness (Horne & Ostberg, 1970), and SAT math questions (“4Tests.com”). The participants were also asked not to put their name anywhere on the packets; instead they were assigned code numbers. Participants were allowed up to 20 minutes to perform these tasks. Once these tasks were completed, participants were debriefed and the experimenter answered participants’ questions.
RESULTS This study utilized 80 female Loyola University students in order to determine the relationship between the variables: time of day, light, and morning- or evening-type. These three independent variables as well as the dependent variable of the SAT math scores were compared by using a 2x2x2 between groups ANOVA test. The means and standard deviations are displayed in Table 2. This information suggests that there is no significant difference in the independent variables, which is apparent in that F(7,72)= 1.481, p= .188. Thus, the null hypothesis could not be rejected.
DISCUSSION Previous research led to the hypothesis that a morning-type person tested in the early morning with direct sunlight would score higher than an evening-type person, as well as score higher than the morning-evening groups tested in florescent lighting. Also, it was predicted that an evening-type person tested in the evening with direct sunlight would score higher than a morning-type person, as well as score higher than the morning-evening groups tested in florescent lighting. The study released by Heschong Mahone Group (1999), which showed that students with the most sunlight in their learning environments exhibited faster, better testing capabilities, supports the hypothesized belief that participants tested in sunlight performed better than those tested in florescent lighting. Also supporting the hypotheses was the study conducted by Anderson, Petros, Beckwith, Mitchell, and Fristz (1991). Congruent to the person’s morning- or evening-type, morning-type participants’ performance decreased as the day progressed, while the evening-type participants’ performance improved as the day progressed. This study’s results should have coincided with the anticipated results of this research’s hypotheses. The results, however, did not support these hypotheses. The results suggested a connection between the variables congruent to past research, yet statistical significance was not acquired. This could be due to the low Power of the experiment set-up since each group contained only ten participants. The access of sunlight could also have been a factor because some days were sunnier than others and the windows were smaller than previously anticipated. Also, depending on the participant’s distance from the windows, their amount of direct sunlight could have differentiated from the other participants, thus either making it hard to see due to too much light or not enough, which in turn would affect their scores. Background noises such as late arrivals of participants or the raucous of people walking by the room may have also contributed to error because of the distraction in concentration. The combined questionnaire was also very long, and therefore some participants may have randomly checked answers instead of working out each math problem. The number of SAT math questions was small, which could have affected the statistical outcome. Many participants had not had math courses in years, and thus, their scores on the math questions may have been affected. In addition, some of the participants’ majors requested more math courses than other majors; therefore, their math abilities may have been influenced by their major requirements. The time limit could have also influenced some participant’s anxiety levels, which could have caused differences in their scoring. Also, some of the morning- or evening-type participants were borderline neither-type, and thus, the results may have been skewed due to the middle range of scores. In the future, research regarding the different effects of lighting should probably be done over a longer period of time. The morning- evening-type participants should also be tested more than once, and a between-group design should be utilized. Overall, this study showed some of the same patterns of data as past research, yet it was not statistically significant. Thus, the experiment should be repeated, yet either with fewer variables or with more Power acquired through a larger sample size. Determining the effects of lighting and a person’s morning- or evening-type could cause a major need for change in learning environments. Past research has shown a difference in testing abilities of morning- and evening-types depending on the time of day. If this was continually researched and the same conclusions resulted, the class schedules would need to be manipulated depending on the student’s morning- or evening-type in order to prevent lower testing and learning abilities due to time of day. Thus, most morning classes should consist of the morning-type people, and the afternoon or evening classes should be for evening-type people. Another alternative could be making special accommodations for evening-type people who must take morning classes, or for morning-type people who must take evening classes. Therefore, the testing and learning abilities would ideally not be influence by the student’s morning- or evening type. If further research continues to show these results, the practical implications would suggest a need for classrooms without windows to change since the absence of sunlight could actually be hindering the testing abilities and learning abilities of the students. Thus, a brighter, sunlit learning environment could lead to further student improvements. Theoretically, these adjustments in the learning environment would lead to healthier, happier, brighter students with better learning and testing abilities. These ideas could also be applied to other activities or areas of life, such as the work force. With changes in the hours required of workers, their circadian rhythms would ideally compare with their scheduled hours. This would lead to personnel who are theoretically more cheerful and healthier. Also, sunlight has been determined to be a necessity for human life, as well as correlationally shown to be a benefit in the classroom environment. If rooms filled with cubicles were discovered to actually hinder the employees’ abilities, then major changes in the environment of businesses may become a necessity. By adding sunlight to darker or florescent-lit environments and paying close attention to personal circadian rhythms, tomorrow’s world may be filled with healthier, smarter, happier people.