## Introduction

People differ in whether they are more of a morning or an evening person. Many people are neither. What you are in this respect is your chronotype.

In daily life, morning types are also known as early birds and evening types night owls.

 A short explanatory video about morning and evening types.
 The "Ch" in "Chronotype" is pronounced as a "k". "Chronos" means time in ancient Greek.

The most used chronotype scale is the Morningness-Eveningness Questionnaire (MEQ) by Horne and Ostberg (1976).

The Circadian Energy Scale (CIRENS) is a two-item scale which correlates with the MEQ, but which is much shorter (2 vs 19 questions).

In the study by Ottoni and colleagues (2011), the CIRENS was tested with 225 college students (18-35 years). In their study, 17.3% were a morning type and 19.6% an evening type (and the rest neither).

### Why is it important?

Chronotype can be related to medical issues and performance. For example, children who are evening types might have difficulties with morning classes, as you can read here.

### Interpretation of the scores.

The CIRENS score ranges from -4 to 4.

Type scores Percentage of student in Ottoni’s study

Morning type

-4, -3, -2

17.3%

Neither type

-1,0,1

63.1%

Evening type

2, 3, 4

19.6%

 Example interpretations: if you score -3, you are a morning type, and if you score between -1 and 1 you are neither a morning nor an evening type.

## Run the demo

It seems that the CIRENS can be used for research, but you need to acknowledge the authors and their research paper when writing about it (Ottoni et al., 2011).

## Technically

This is a simple scale question. The calc type is used to calculate the score.

## The survey code for PsyToolkit

Copy and paste this code to your PsyToolkit account if you want to use the scale in your own online research project
```scale: energy
- very low
- low
- moderate
- high
- very high

l: cirens
t: scale energy
o: width 50%
q: In general, how is your energy level in the morning and in the evening?
- In the <b>morning</b>
- In the <b>evening</b>

l: score
t: set
- calc \$cirens.2 - \$cirens.1

l: feedback
t: info
q: Your Cirens Score is {\$score}.<b><br><br>
A score of -2 or lower means you are a morning type.<br>
A score of 2 or higher means you are an evening type.<br>
A score in between means you are neither.<br>```

## References

• Horne and Ostberg (1976). A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. International Journal of Chronobiology, 4, 97–110.

• Ottoni, G.L., Antoniolli, E., & Lara, D.R. (2011). The Circadian Energy Scale (CIRENS): Two Simple Questions for a Reliable Chronotype Measurement Based on Energy. Chronobiology International, 28, 229-337.