Introduction: Globalisation increases the need for suitable “quality of life” (QOL) measures suitable for cross-national comparison or aggregation of data across cultures. QOL as a construct is noted to be influenced by many factors such as, socio-demographical and cultural variables. It is important, therefore, to ensure that an instrument developed in one culture is valid in another. In measuring SWB, some researchers prefer using a horizontal format of Visual Analogue Scale (VAS), while others opt for a vertical presentation of the VAS. However, some investigators suggested that the scales’ orientation and the type of VAS may affect the respondent’s response. Aims: The current study, including two experiments, was designed to compare the sensitivity ACSA (1) to cultural differences, (2) to some socioeconomic and demographic variables and (3) to variations in response format. Experiment 1: A sample of 424 volunteers, Iranians= 83, (teachers, 29 % females), and Belgians= 341, (students, 72 % females), rated their current SWB on the Anamnestic Comparative Self Assessment scale (ACSA), a rating scale for global SWB. Besides some socio demographic data were collected. The results of independent t-test comparing the mean and Levene’s test to compare variances of SWB of the two surveyed samples (Iranians and Belgians) revealed no significant difference between score means (MIran= 70.48, MBelgium=70.75) (t (422) = .11, P< .91) of SWB rating and also variances of scores of SWB ratings of two samples (SDIran= 19.81, SDBelgium=19.91) (F= .26, P= .61). Meanwhile, using Univariate Analysis of Variance (ANCOVA) a significant main effect of (1) gender (F (1, 45) = 5.57, P= .023) was found in Iranian sample (not Belgian sample). Experiment 2: A sample of 24 male and 124 female undergraduate students (M age= 19.10) who assigned randomly to three groups, were asked to rate their current overall SWB on the (ACSA). The ACSA presented in three formats: two equivalent vertical and horizontal bipolar scales and a numerical ...