Return to the Game of Chicken page
___________________________________________________________________________________________________________________	

									THE HUNGRY MONKEY GAME (dove-hawk paradigm)
___________________________________________________________________________________________________________________	

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
last updated:  03-13-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-13-2020 Millisecond Software

___________________________________________________________________________________________________________________
BACKGROUND INFO 	
___________________________________________________________________________________________________________________	
This script runs an experiment designed for kids based on the dove-hawk paradigm (aka Game of Chicken)*. 
The basic premise of the dove-hawk  paradigm is that two people compete for the same resources and have to decide to 
(a) take the resources fast or (b) wait for the opponent's decision. 
If they decide to take the resource they can either win the resource (=> the other person waited) or experience 
a  devastating loss (=>the other person also went for the resource). If they wait they either don't get the resource (=> the other
person went for the resource) or are able to share it (=> the other person also waited).

*Reference for Dove-Hawk Paradigm (aka Game of Chicken): http://en.wikipedia.org/wiki/Chicken_(game)

___________________________________________________________________________________________________________________
TASK DESCRIPTION	
___________________________________________________________________________________________________________________
In this experiment, kids are asked to collect as many bananas as they can for a hungry monkey named "Charly" while competing
with a (computer-generated) "second player", e.g. "Alex"*. In order to decide if they want to 
a) wait to see what the opponent is doing (=dove behavior) or 
b) take the bananas right away (=hawk behavior) 
they have to consider the following rules that determine the outcome of their decisions:

1) If the participant takes the bananas and the opponent waits, the participant gets the full amount of the offered bananas
2) If the opponent takes the bananas and the participant waits, the participant neither wins nor loses any bananas
3) If the opponent and the participant wait, they equally share the bananas (each gets half)
4) If both take the bananas, they each lose double the amount of bananas offered

___________________________________________________________________________________________________________________	
DURATION 
___________________________________________________________________________________________________________________	
the default set-up of the script takes appr. XXX minutes to complete
(if no task duration is provided, please contact Millisecond Software
(katjab@millisecond.com)

___________________________________________________________________________________________________________________	
DATA FILE INFORMATION 
___________________________________________________________________________________________________________________
The default data stored in the data files are:

(1) Raw data file: 'dovehawk_raw*.iqdat' (a separate file for each participant)

build:								The specific Inquisit version used (the 'build') that was run
computer.platform:					the platform the script was run on (win/mac/ios/android)
date, time, 						date and time script was run 
subject, group, 					with the current subject/groupnumber
script.sessionid:					with the current session id

blockcode, blocknum:				the name and number of the current block (built-in Inquisit variable)
trialcode, trialnum: 				the name and number of the currently recorded trial (built-in Inquisit variable)
										Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those
										that do not store data to the data file such as feedback trials. Thus, trialnum 
										may not reflect the number of main trials run per block. 
										
opponent_name:						name of the current opponent
p_hawk:								probability of hawk-strategy (likelihood that opponent "takes" the bananas)
winamount:							current amount of bananas that can be won
comp_strategy:						opponent's decision: 1 = hawk (=take), 0 = dove (=wait)
response:							the response box that participant clicked 
p_response:							participant's choice: 1 = hawk (take), 0 = dove (=wait) (interpretation of selected response box)
latency:							time it took participant to make a choice in ms (once the response boxes were presented)
outcome:							the outcome of the "fight": 1 = opponent wins, 2 = participant wins, 3 = both lose, 4 = compromise
p_total:							the total sum of bananas won at this time

	
(2) Summary data file: 'dovehawk_summary*.iqdat' (a separate file for each participant)

computer.platform:					the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:						assigned group id number
script.sessionid:					assigned session id number
script.elapsedtime:					time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
									1 = script was completed (all conditions run)
								
p_total:							the total sum of bananas won


___________________________________________________________________________________________________________________	
EXPERIMENTAL SET-UP 
___________________________________________________________________________________________________________________
The experiment offers 3 basic blocks that vary the probability with which the computer-generated opponent decides to take bananas
 (=hawk) or wait (=dove):
1) Mixed Block: 	p(hawk) = 0.5
2) Hawk: 		p(hawk) = 0.8
3) Dove:			p(hawk) = 0.2

In each of these blocks, participants are presented with 15 trials in which they have to make a dove-hawk decision.
The name of the opponent for each block is randomly pulled from a pool of 3 gender-neutral names 
Note: if trial sequence needs a build-in delay, there are several editable parameter that can be set to accomplish a delay.

A second round of the three basic blocks continuously increases the amount of bananas that can be won by 2 
(max amount of bananas that can be won = 30, max of bananas that can be lost = 60).

___________________________________________________________________________________________________________________	
STIMULI
___________________________________________________________________________________________________________________	
provided by Millisecond Software - check under section EDITABLE STIMULI

___________________________________________________________________________________________________________________	
INSTRUCTIONS 
___________________________________________________________________________________________________________________
provided by Millisecond Software - check under section EDITABLE INSTRUCTIONS

___________________________________________________________________________________________________________________	
EDITABLE CODE 
___________________________________________________________________________________________________________________	
check below for (relatively) easily editable parameters, stimuli, instructions etc. 
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code 
to further customize your experiment.

The parameters you can change are:

to build in delays:
skipdelay:						false = delay trials are run
								true = delay trials are not run (default)
								
responseboxdelay:				delay of the response boxes in ms (default: 0ms)
posttrialpause_choice:			default = 0 ms
delayduration:					the duration of the delay trial in ms (default: 5000ms) - runs only if skipdelay = false
posttrialpause_feedback:		default = 0 ms
nextdelay:						delay of the 'continue/next' buttons after feedback was given (default: 0ms)


to change these variables, also change the corresponding lists under "EDITABLE LISTS":
pr_mixed:						sets the probability of hawk strategy in the mixed condition, here: 0.5
pr_hawk:						sets the probability of hawk strategy in the hawk condition, here: 0.8
pr_dove:						sets the probability of hawk strategy in the dove condition, here:0.2